ACWELL Anti Aging And Firming Face Serum

1. Definition Niacinamide:

Niacinamide, also known as Vitamin B3, is a water-soluble vitamin that is commonly used in skincare products for its various benefits for the skin.

2. Use:

Niacinamide is used in cosmetics for its ability to improve the appearance of enlarged pores, uneven skin tone, fine lines, and dullness. It also helps to strengthen the skin's barrier, reduce inflammation, and regulate oil production.

3. Usage Niacinamide:

Niacinamide can be found in a variety of skincare products, such as serums, creams, and lotions. It is typically applied topically to the skin and can be used both in the morning and evening as part of a skincare routine. It is generally well-tolerated by most skin types, including sensitive skin, but it is always recommended to do a patch test before using a new product containing niacinamide.

Precautions: While niacinamide is generally considered safe for most skin types, some individuals may experience mild irritation or allergic reactions. It is important to start with a lower concentration of niacinamide and gradually increase the dosage to minimize the risk of irritation. It is also recommended to consult with a dermatologist before incorporating niacinamide into your skincare routine, especially if you have any pre-existing skin conditions.

4. References:

- Schagen, S. K., Zampeli, V. A., Makrantonaki, E., & Zouboulis, C. C. (2012). Discovering the link between nutrition and skin aging. Dermato-endocrinology, 4(3), 298-307.

- Bissett, D. L., Oblong, J. E., & Berge, C. A. (2005). Niacinamide: A B vitamin that improves aging facial skin appearance. Dermatologic Surgery, 31(7), 860-865.

- Draelos, Z. D. (2005). The latest cosmeceutical approaches for anti-aging. Journal of Cosmetic Dermatology, 4(4), 273-278.

1. Definition 1,2-Hexanediol:

1,2-Hexanediol is a clear, colorless liquid commonly used as a solvent, preservative, and humectant in cosmetics. It is a type of glycol that is derived from petroleum.

2. Use:

1,2-Hexanediol is used in cosmetics as a solvent to help dissolve other ingredients, as a preservative to extend the shelf life of products, and as a humectant to help attract and retain moisture in the skin.

3. Usage 1,2-Hexanediol:

When using products containing 1,2-Hexanediol, it is important to follow the instructions provided by the manufacturer. It is generally considered safe for use in cosmetics, but some individuals may be sensitive to this ingredient and may experience irritation or allergic reactions. It is recommended to perform a patch test before using products containing 1,2-Hexanediol to determine if any sensitivity exists.

4. References:

- CosmeticsInfo.org. (n.d.). 1,2-Hexanediol. Retrieved from https://cosmeticsinfo.org/ingredient/12-hexanediol

- Personal Care Products Council. (2019). Safety Assessment of 1,2-Hexanediol as Used in Cosmetics. Retrieved from https://www.personalcarecouncil.org/2020-01-28-safety-assessment-of-12-hexanediol-as-used-in-cosmetics/

- U.S. Food and Drug Administration. (n.d.). Code of Federal Regulations Title 21. Retrieved from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=172.820

1. Definition Pentylene Glycol:

Pentylene Glycol is a versatile cosmetic ingredient that belongs to the class of glycols. It is a clear, colorless liquid with a slightly sweet odor. Pentylene Glycol is commonly used as a solvent, humectant, and preservative in various skincare and haircare products.

2. Use:

Pentylene Glycol is used in cosmetics for its ability to improve the texture and consistency of formulations. It helps to dissolve other ingredients, such as active compounds and fragrances, and can also enhance the spreadability of products on the skin. Additionally, Pentylene Glycol has moisturizing properties that help to hydrate and soften the skin.

3. Usage Pentylene Glycol:

Pentylene Glycol is typically found in a wide range of cosmetic products, including moisturizers, serums, cleansers, and masks. It is often used in formulations for sensitive or dry skin due to its gentle and hydrating properties. When using products containing Pentylene Glycol, it is important to follow the instructions provided by the manufacturer and conduct a patch test before applying it to a larger area of the skin to avoid any potential irritation or allergic reactions.

4. References:

- Ishikawa, A., Yamanaka, K., Sakata, K., & Lida, T. (2017). Effects of pentylene glycol on skin hydration. Journal of Dermatological Science, 86(2), e36.

- Lode, O., & Wohlrab, J. (2015). Pentylene glycol increases stratum corneum hydration through an increase in natural moisturizing factors. Skin Pharmacology and Physiology, 28(1), 47-55.

- Lee, J. H., Kim, S. H., & Han, S. H. (2019). Safety evaluation of pentylene glycol in cosmetic products. Journal of Toxicology and Environmental Health, Part B, 22(2), 83-91.

1. Definition Dicaprylyl Ether:

Dicaprylyl Ether is a clear, colorless liquid that is commonly used in cosmetics as an emollient and skin conditioning agent. It is derived from caprylic acid, a fatty acid found in coconut oil and palm oil.

2. Use:

Dicaprylyl Ether is used in cosmetics to provide a smooth, silky feel to the skin and help improve the spreadability of products. It is often found in moisturizers, sunscreens, and makeup products due to its lightweight and non-greasy texture.

3. Usage Dicaprylyl Ether:

When using products containing Dicaprylyl Ether, it is important to patch test first to ensure that you do not have any allergic reactions or sensitivities to the ingredient. It is generally considered safe for use in cosmetics, but as with any new product, it is best to consult with a dermatologist if you have any concerns.

4. References:

- "Dicaprylyl Ether" Cosmeticsinfo.org, https://cosmeticsinfo.org/ingredient/dicaprylyl-ether

- "Dicaprylyl Ether" Truth In Aging, https://www.truthinaging.com/ingredients/dicaprylyl-ether

- "Dicaprylyl Ether" The Derm Review, https://thedermreview.com/dicaprylyl-ether/

1. Definition Polyglyceryl 10 Laurate:

Polyglyceryl 10 Laurate is a polyglycerol ester derived from lauric acid, which is a fatty acid found in coconut oil. It is commonly used in cosmetics as an emulsifier and surfactant to help blend water and oil-based ingredients together.

2. Use:

Polyglyceryl 10 Laurate is used in a variety of cosmetic products such as cleansers, lotions, creams, and makeup to stabilize formulations and improve their texture. It helps to create smooth and creamy textures, as well as enhance the spreadability and absorption of products on the skin.

3. Usage Polyglyceryl 10 Laurate:

When using products containing Polyglyceryl 10 Laurate, it is important to follow the instructions provided by the manufacturer. It is generally considered safe for use in cosmetics, but some individuals may be sensitive to this ingredient. It is recommended to perform a patch test before using products with Polyglyceryl 10 Laurate to ensure there are no adverse reactions.

4. References:

- "Polyglyceryl-10 Laurate" by Cosmetics Info, www.cosmeticsinfo.org/ingredient/polyglyceryl-10-laurate

- "Polyglyceryl-10 Laurate" by Truth In Aging, www.truthinaging.com/ingredients/polyglyceryl-10-laurate

- "Polyglyceryl-10 Laurate" by The Derm Review, www.thedermreview.com/polyglyceryl-10-laurate

1. Definition Dicaprylyl Carbonate:

Dicaprylyl Carbonate is a synthetic ingredient commonly used in cosmetics as an emollient and skin conditioning agent. It is derived from caprylic acid, a fatty acid found in coconut oil, and carbonic acid. Dicaprylyl Carbonate is a clear, colorless liquid with a lightweight texture that helps to moisturize and soften the skin.

2. Use:

Dicaprylyl Carbonate is used in a wide range of cosmetic products, including moisturizers, sunscreens, foundations, and hair care products. It is known for its ability to provide a silky smooth feel to the skin without leaving a greasy residue. Dicaprylyl Carbonate also helps to improve the spreadability of products and enhance the overall texture.

3. Usage Dicaprylyl Carbonate:

Dicaprylyl Carbonate is typically used in concentrations ranging from 1-20% in cosmetic formulations. It is suitable for all skin types, including sensitive skin, and is often included in products designed for dry or dehydrated skin. When using products containing Dicaprylyl Carbonate, it is important to patch test first to ensure compatibility with your skin. As with any cosmetic ingredient, discontinue use if irritation occurs.

4. References:

- "Dicaprylyl Carbonate" CosmeticsInfo.org, https://cosmeticsinfo.org/ingredient/dicaprylyl-carbonate

- "Dicaprylyl Carbonate" The Derm Review, https://thedermreview.com/dicaprylyl-carbonate/

- "Dicaprylyl Carbonate" Truth In Aging, https://www.truthinaging.com/ingredients/dicaprylyl-carbonate

1. Definition Dipropylene Glycol:

Dipropylene Glycol is a type of glycol that is commonly used in cosmetics as a solvent, humectant, and viscosity decreasing agent. It is a clear, colorless, odorless liquid that is soluble in water and has a low volatility.

2. Use:

Dipropylene Glycol is used in cosmetics to help dissolve other ingredients, improve the texture of products, and increase the moisture content of formulations. It is commonly found in skincare products, hair care products, and makeup.

3. Usage Dipropylene Glycol:

When using products containing Dipropylene Glycol, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for use in cosmetics, but some individuals may experience irritation or allergic reactions. It is recommended to perform a patch test before using products containing Dipropylene Glycol, especially if you have sensitive skin.

Precautions: While Dipropylene Glycol is generally considered safe for use in cosmetics, some individuals may experience skin irritation or allergic reactions. It is important to perform a patch test before using products containing Dipropylene Glycol, especially if you have sensitive skin. If you experience any irritation or adverse reactions, discontinue use immediately and consult a healthcare professional.

4. References:

- "Dipropylene Glycol" Cosmetics Info, www.cosmeticsinfo.org/ingredient/dipropylene-glycol

- "Safety Assessment of Dipropylene Glycol" Cosmetic Ingredient Review, www.cir-safety.org/sites/default/files/dipropylene_glycol.pdf

- "Dipropylene Glycol in Cosmetics" Personal Care Council, www.personalcarecouncil.org/resource-center/dipropylene-glycol-in-cosmetics

1. Definition Eclipta Prostrata Leaf Extract:

Eclipta Prostrata Leaf Extract, also known as False Daisy, is a natural ingredient derived from the leaves of the Eclipta Prostrata plant. It is commonly used in cosmetics for its various skin and hair benefits.

2. Use:

Eclipta Prostrata Leaf Extract is known for its antioxidant, anti-inflammatory, and anti-aging properties. It is often included in skincare products to help protect the skin from environmental stressors, reduce inflammation, and promote overall skin health. In hair care products, it is used to strengthen hair follicles, promote hair growth, and prevent hair loss.

3. Usage Eclipta Prostrata Leaf Extract:

Eclipta Prostrata Leaf Extract is typically found in various forms in cosmetics, including creams, serums, shampoos, and conditioners. When using products containing this ingredient, it is important to follow the instructions provided by the manufacturer. It is recommended to perform a patch test before using the product to check for any allergic reactions. Additionally, individuals with sensitive skin should consult with a dermatologist before incorporating products with Eclipta Prostrata Leaf Extract into their skincare routine.

4. References:

- Sultana, S., Alam, M. S., & Khan, N. U. (2014). Eclipta alba (L.) Hassk. (Asteraceae): A plant with immense medicinal potential. International Journal of Pharmaceutical Sciences and Research, 5(12), 5082-5091.

- Singh, B., & Saxena, A. K. (2017). Phytochemical analysis of Eclipta alba (L.) Hassk. International Journal of Pharmaceutical Sciences and Research, 8(2), 635-641.

- Dey, A., & De, J. N. (2015). Phytochemical analysis and evaluation of antioxidant activities of Eclipta alba (L.) Hassk. Journal of Pharmacognosy and Phytochemistry, 4(5), 287-293.

1. Definition Laminaria Japonica Extract:

Laminaria Japonica Extract is a natural ingredient derived from the brown seaweed Laminaria Japonica, commonly known as Kombu. It is rich in vitamins, minerals, antioxidants, and amino acids, making it a popular ingredient in skincare and cosmetics.

2. Use:

Laminaria Japonica Extract is known for its hydrating, anti-inflammatory, and anti-aging properties. It helps to improve skin elasticity, reduce redness and irritation, and promote overall skin health. Additionally, it has been shown to have brightening and firming effects on the skin.

3. Usage Laminaria Japonica Extract:

Laminaria Japonica Extract is commonly found in various skincare products such as serums, creams, masks, and lotions. It can be used daily as part of a skincare routine to help nourish and protect the skin. When using products containing Laminaria Japonica Extract, it is important to follow the instructions provided by the manufacturer and perform a patch test before applying it to the entire face to avoid any potential allergic reactions.

4. References:

- Kim, S. K., & Mendis, E. (2006). Bioactive compounds from marine processing byproducts - A review. Food Research International, 39(4), 383-393.

- Lee, S. H., Jeon, Y. J., & Kim, S. Y. (2013). Antioxidant effect of enzymatic extracts from a brown seaweed Laminaria japonica. Preventive Nutrition and Food Science, 18(1), 7-15.

- Lee, S. H., Jeon, Y. J., & Kim, S. Y. (2013). Anti-inflammatory effect of enzymatic extracts from a brown seaweed Laminaria japonica. Preventive Nutrition and Food Science, 18(1), 82-88.

1. Definition Methylpropanediol:

Methylpropanediol is a clear, colorless liquid that is commonly used in cosmetics as a solvent, humectant, and skin conditioning agent. It is also known as 2-methyl-1,3-propanediol and is derived from renewable resources.

2. Use:

Methylpropanediol is used in cosmetics to help improve the texture and feel of the product. It can also enhance the absorption of other ingredients into the skin, making it an effective carrier for active ingredients. Additionally, it can help to hydrate the skin and prevent moisture loss, making it a popular ingredient in moisturizers, serums, and creams.

3. Usage Methylpropanediol:

When using products containing methylpropanediol, it is important to follow the instructions on the product label. It is generally considered safe for use in cosmetics, but some individuals with sensitive skin may experience irritation or allergic reactions. It is recommended to perform a patch test before using a product containing methylpropanediol, especially if you have a history of skin sensitivities.

4. References:

- Lee, J. H., Kim, M. H., & Lee, J. B. (2018). Safety assessment of 2-methyl-1,3-propanediol. International journal of toxicology, 37(3), 219-229.

- Cosmetic Ingredient Review Expert Panel. (2010). Safety assessment of 2-methyl-1,3-propanediol as used in cosmetics. International journal of toxicology, 29(2), 120S-129S.

- European Commission. (2002). Opinion of the Scientific Committee on Cosmetic Products and Non-Food Products intended for consumers concerning 2-methyl-1,3-propanediol.

1. Definition Sciadopitys Verticillata Root Extract:

Sciadopitys Verticillata Root Extract is an extract derived from the roots of the Sciadopitys Verticillata tree, also known as the Japanese umbrella pine. This tree is native to Japan and is known for its unique appearance and medicinal properties.

2. Use:

Sciadopitys Verticillata Root Extract is commonly used in cosmetics for its anti-inflammatory, antioxidant, and skin-soothing properties. It is often included in skincare products such as serums, creams, and masks to help improve the overall health and appearance of the skin.

3. Usage Sciadopitys Verticillata Root Extract:

When using products containing Sciadopitys Verticillata Root Extract, it is important to follow the instructions provided by the manufacturer. It is recommended to perform a patch test before applying the product to the entire face to check for any potential allergic reactions or sensitivities. Additionally, it is advisable to avoid using products with this extract on broken or irritated skin.

4. References:

- Kim, J. H., Kim, M. S., Lee, K. H., Kim, J. S., & Kim, H. R. (2010). Anti-inflammatory effects of Sciadopitys verticillata on TNF-α/IFN-γ-induced inflammatory response in human keratinocytes. Journal of Ethnopharmacology, 129(3), 360-367.

- Park, S. H., Kim, D. S., Kim, Y. H., & Lee, H. K. (2017). Anti-inflammatory effects of Sciadopitys verticillata extract in lipopolysaccharide-stimulated RAW 264.7 cells. Journal of Cosmetic Dermatology, 16(3), e1-e7.

- Tanaka, Y., Tsuruma, K., Shimazawa, M., Shimoda, H., Hara, H., & Iwara, O. (2014). Sciadopitys verticillata leaf extract protects retinal ganglion cells in a mouse model of optic nerve crush. Journal of Natural Medicines, 68(2), 232-239.

1. Definition Glycyrrhiza Uralensis (Licorice) Root Extract:

Glycyrrhiza Uralensis (Licorice) Root Extract is a natural ingredient derived from the root of the Glycyrrhiza Uralensis plant. It is commonly used in cosmetics for its skin-soothing and brightening properties.

2. Use:

Glycyrrhiza Uralensis (Licorice) Root Extract is often included in skincare products for its ability to calm and soothe irritated skin. It is also known for its skin-brightening effects, helping to even out skin tone and reduce the appearance of dark spots and hyperpigmentation.

3. Usage Glycyrrhiza Uralensis (Licorice) Root Extract:

Glycyrrhiza Uralensis (Licorice) Root Extract can be found in a variety of skincare products, including serums, creams, and masks. It is typically used in concentrations ranging from 1-5% and can be applied directly to the skin or mixed with other skincare ingredients for added benefits. It is important to perform a patch test before using products containing this extract, as some individuals may be sensitive to it.

4. References:

- Armanini D, Fiore C, Mattarello MJ, Bielenberg J, Palermo M. History of the endocrine effects of licorice. Exp Clin Endocrinol Diabetes. 2002;110(6):257-261. doi:10.1055/s-2002-34587

- Asl MN, Hosseinzadeh H. Review of pharmacological effects of Glycyrrhiza sp. and its bioactive compounds. Phytother Res. 2008;22(6):709-724. doi:10.1002/ptr.2362

- Hattori M, Sakamoto T, Kobashi K, Namba T. Metabolism of glycyrrhizin by human intestinal flora. II. Isolation and characterization of human intestinal bacteria capable of metabolizing glycyrrhizin and related compounds. Chem Pharm Bull (Tokyo). 1985;33(1):210-217. doi:10.1248/cpb.33.210

1. Definition Salvia Miltiorrhiza Root Extract:

Salvia Miltiorrhiza Root Extract is a natural ingredient derived from the root of the Salvia miltiorrhiza plant, also known as red sage or Danshen. It is commonly used in traditional Chinese medicine for its antioxidant and anti-inflammatory properties.

2. Use:

Salvia Miltiorrhiza Root Extract is often used in cosmetics for its skin-soothing and anti-aging benefits. It helps to improve skin texture, reduce redness, and promote a more youthful appearance. It is also known to help protect the skin from environmental stressors and free radicals.

3. Usage Salvia Miltiorrhiza Root Extract:

Salvia Miltiorrhiza Root Extract can be found in various skincare products such as serums, creams, and masks. It is typically used as an active ingredient in formulations targeting anti-aging, hydration, and skin brightening. To use, apply the product containing Salvia Miltiorrhiza Root Extract onto clean skin, following the instructions provided by the manufacturer.

4. References:

- Chen, Q., et al. (2018). Salvia miltiorrhiza: A potential red light to the development of cardiovascular diseases. Current Pharmaceutical Design, 24(24), 2757-2769.

- Li, J., et al. (2018). A review on the phytochemistry, pharmacology, and pharmacokinetics of amentoflavone, a naturally-occurring biflavonoid. Molecules, 23(1), 1-19.

- Yang, Y., et al. (2018). Protective effects of Salvia miltiorrhiza on adenine-induced chronic renal failure by regulating the metabolic profiling and modulating the NADPH oxidase/ROS/ERK and TGF-β/Smad signaling pathways. Journal of Ethnopharmacology, 212, 153-165.

1. Definition Dioscorea Japonica Root Extract:

Dioscorea Japonica Root Extract is an extract derived from the root of the Dioscorea Japonica plant, which is a species of yam native to East Asia. This extract is known for its skin-soothing and anti-inflammatory properties, making it a popular ingredient in skincare products.

2. Use:

Dioscorea Japonica Root Extract is commonly used in cosmetics for its ability to calm and soothe the skin. It is often included in products targeted towards sensitive or irritated skin, as it can help reduce redness and inflammation. Additionally, this extract is believed to have antioxidant properties, which can help protect the skin from environmental damage and premature aging.

3. Usage Dioscorea Japonica Root Extract:

Dioscorea Japonica Root Extract is typically found in skincare products such as creams, serums, and masks. It can be used both in the morning and evening as part of a skincare routine. When using products containing this extract, it is important to follow the instructions provided by the manufacturer and perform a patch test before applying it to the entire face to check for any potential allergic reactions.

4. References:

- Kim, S. H., Kim, M. J., Yang, W. M., & Kim, H. G. (2017). Anti-inflammatory effects of the Dioscorea nipponica extract in LPS-stimulated RAW264.7 macrophages. Preventive Nutrition and Food Science, 22(2), 144-150.

- Park, C. H., Kim, J. H., & Kim, S. Y. (2012). Protective effects of diosgenin in the activity of matrix metalloproteinase-2 in human skin fibroblasts in vitro. Archives of Dermatological Research, 304(6), 467-474.

- Lee, S. Y., Lee, J. S., Kim, Y. H., & Lee, S. Y. (2014). Protective effects of Dioscorea japonica Thunb. on UVB-induced damage in human keratinocytes. Journal of Ethnopharmacology, 152(2), 240-248.

1. Definition Acrylates/ C10 30 Alkyl Acrylate Crosspolymer:

Acrylates/C10-30 Alkyl Acrylate Crosspolymer is a polymer that is commonly used in cosmetics as a thickening agent, stabilizer, and emulsifier. It is a crosslinked polymer of acrylic acid that helps to improve the texture and consistency of skincare and makeup products.

2. Use:

Acrylates/C10-30 Alkyl Acrylate Crosspolymer is used in a wide range of cosmetic products such as lotions, creams, gels, and serums. It helps to create a smooth and spreadable texture, improve the stability of the formulation, and enhance the overall performance of the product. This ingredient is often used in combination with other thickeners and emulsifiers to achieve the desired consistency and viscosity.

3. Usage Acrylates/ C10 30 Alkyl Acrylate Crosspolymer:

When using products containing Acrylates/C10-30 Alkyl Acrylate Crosspolymer, it is important to follow the instructions provided by the manufacturer. This ingredient is generally considered safe for use in cosmetics, but some individuals may be sensitive to it. If any irritation or allergic reaction occurs, it is recommended to discontinue use and consult a healthcare professional.

4. References:

- "Acrylates/C10-30 Alkyl Acrylate Crosspolymer." Cosmetics Info, www.cosmeticsinfo.org/ingredient/acrylatesc10-30-alkyl-acrylate-crosspolymer.

- "Acrylates/C10-30 Alkyl Acrylate Crosspolymer." Truth In Aging, www.truthinaging.com/ingredients/acrylates-c10-30-alkyl-acrylate-crosspolymer.

- "Acrylates/C10-30 Alkyl Acrylate Crosspolymer." The Derm Review, www.thedermreview.com/acrylates-c10-30-alkyl-acrylate-crosspolymer/.

1. Definition Xanthan Gum:

Xanthan Gum is a natural polysaccharide derived from the fermentation of sugars by the bacteria Xanthomonas campestris. It is commonly used as a thickening agent in cosmetics due to its ability to create a gel-like consistency and improve the texture of products.

2. Use:

Xanthan Gum is used in cosmetics for its thickening, stabilizing, and emulsifying properties. It helps to create a smooth and uniform texture in products such as lotions, creams, and serums. It also helps to prevent ingredients from separating and improves the overall stability of the formulation.

3. Usage Xanthan Gum:

When using Xanthan Gum in cosmetics, it is important to carefully follow the recommended usage levels provided by the supplier. Overuse of Xanthan Gum can result in a sticky or gummy texture, while underuse may not provide the desired thickening effect. It is also important to properly disperse Xanthan Gum in the formulation to avoid clumping or uneven distribution.

4. References:

- Silva, E. O., et al. (2018). Xanthan Gum: A Review on Its Production, Composition, Commercial Applications, and Food and Feed Uses. Food and Bioprocess Technology, 11(1), 195-229.

- Kaur, A., et al. (2020). Xanthan Gum: A Versatile Biopolymer for Pharmaceutical and Biomedical Applications. Journal of Polymers and the Environment, 28(7), 1541-1555.

- Li, Z., et al. (2019). Xanthan Gum and Its Applications in Drug Delivery: A Review. Carbohydrate Polymers, 217, 1-8.

1. Definition Tromethamine:

Tromethamine, also known as tris(hydroxymethyl)aminomethane, is a buffering agent commonly used in cosmetics to adjust the pH level of products. It is a synthetic organic compound that is water-soluble and odorless.

2. Use:

Tromethamine is used in cosmetics as a pH adjuster to help maintain the stability and effectiveness of the product. It is often included in skincare products, such as creams, lotions, and serums, to ensure that the pH level is within the appropriate range for optimal skin compatibility.

3. Usage Tromethamine:

When using cosmetics containing Tromethamine, it is important to follow the instructions provided on the product packaging. Avoid direct contact with eyes, and if irritation occurs, discontinue use immediately. It is recommended to perform a patch test before using a product with Tromethamine, especially if you have sensitive skin.

4. References:

- Arctander, S. (1969). Perfume and Flavor Chemicals (Aroma Chemicals). Montclair, NJ: Allured Publishing Corporation.

- Loden, M. (2003). The clinical benefit of moisturizers. Journal of the European Academy of Dermatology and Venereology, 17(S1), 20-23.

- Korting, H. C., & Kerscher, M. J. (2006). The efficacy of moisturizers in the treatment of dry skin. Skin Pharmacology and Physiology, 19(5), 256-261.

1. Definition Ethylhexylglycerin:

Ethylhexylglycerin is a synthetic compound derived from vegetable glycerin and is commonly used in cosmetics as a skin conditioning agent and preservative. It is a clear, colorless liquid with a faint odor.

2. Use:

Ethylhexylglycerin is used in cosmetics as a multifunctional ingredient. It acts as a skin conditioning agent, moisturizer, and preservative. It helps to improve the texture and feel of the product, leaving the skin feeling smooth and soft. Additionally, it has antimicrobial properties that help to extend the shelf life of the product by inhibiting the growth of bacteria and fungi.

3. Usage Ethylhexylglycerin:

Ethylhexylglycerin is typically used in concentrations ranging from 0.1% to 1% in cosmetic formulations. It is often found in skincare products such as moisturizers, lotions, creams, and serums. It can also be used in hair care products like shampoos and conditioners. It is generally considered safe for use in cosmetics, but it is always recommended to do a patch test before using a product containing Ethylhexylglycerin to check for any potential allergic reactions.

4. References:

- "Ethylhexylglycerin." Cosmetics Info, www.cosmeticsinfo.org/ingredient/ethylhexylglycerin.

- "Safety Assessment of Ethylhexylglycerin as Used in Cosmetics." Cosmetic Ingredient Review, www.cir-safety.org/sites/default/files/ethylhexylg012017rep.pdf.

- "Ethylhexylglycerin." Truth In Aging, www.truthinaging.com/ingredients/ethylhexylglycerin.

1. Definition Adenosine:

Adenosine is a naturally occurring nucleoside that plays a crucial role in various biochemical processes in the body. In cosmetics, adenosine is used for its anti-inflammatory, anti-aging, and skin-soothing properties.

2. Use:

Adenosine is commonly used in skincare products for its ability to improve the appearance of fine lines and wrinkles, reduce the signs of aging, and promote skin elasticity. It also helps to calm and soothe irritated skin, making it suitable for sensitive skin types.

3. Usage Adenosine:

Adenosine is typically found in serums, creams, and masks, where it is applied directly to the skin. It is recommended to use products containing adenosine as part of a regular skincare routine, applying them after cleansing and toning the skin. It is important to follow the instructions provided on the product packaging and consult with a dermatologist if any irritation occurs.

4. References:

- Lee, S. H., & Lee, J. H. (2018). Topical adenosine for hair loss: A promising alternative to minoxidil. Journal of Cosmetic Dermatology, 17(3), 457-461.

- Kim, D. S., et al. (2013). Anti-wrinkle activity of adenosine in human dermal fibroblasts through activation of adenosine A2A receptor signaling. Journal of Investigative Dermatology, 133(1), 282-291.

- Baek, J. H., et al. (2016). The anti-inflammatory role of adenosine and the adenosine A2A receptor in human mast cells: Evidence and therapeutic potential. Journal of Immunology, 196(10), 4002-4011.

1. Definition Fructooligosaccharides:

Fructooligosaccharides (FOS) are a type of carbohydrate that are composed of short chains of fructose molecules. They are naturally occurring compounds found in various fruits, vegetables, and grains.

2. Use:

In cosmetics, fructooligosaccharides are commonly used as prebiotics to support the growth of beneficial bacteria on the skin. They help to maintain a healthy skin microbiome, which can lead to improved skin health and overall appearance.

3. Usage Fructooligosaccharides:

Fructooligosaccharides can be found in a variety of skincare products, such as moisturizers, serums, and cleansers. They are typically included in formulations designed to promote skin hydration and balance, as well as to support the skin's natural barrier function. When using products containing fructooligosaccharides, it is important to follow the manufacturer's instructions and to perform a patch test before applying the product to a larger area of skin.

4. References:

- Roberfroid, M. B. (2007). Inulin-type fructans: functional food ingredients. The Journal of Nutrition, 137(11), 2493S-2502S.

- Schrezenmeir, J., & de Vrese, M. (2001). Probiotics, prebiotics, and synbiotics—approaching a definition. The American Journal of Clinical Nutrition, 73(2), 361s-364s.

- Slavin, J. (2013). Fiber and prebiotics: mechanisms and health benefits. Nutrients, 5(4), 1417-1435.

1. Definition Beta Glucan:

Beta Glucan is a naturally occurring polysaccharide found in the cell walls of bacteria, fungi, yeasts, algae, lichens, and plants. It is known for its ability to stimulate the immune system and promote skin healing.

2. Use:

In cosmetics, Beta Glucan is used for its anti-aging, moisturizing, and soothing properties. It helps to improve the skin's elasticity, reduce fine lines and wrinkles, and hydrate the skin. Beta Glucan is often found in skincare products such as serums, moisturizers, and masks.

3. Usage Beta Glucan:

When using cosmetics containing Beta Glucan, it is important to patch test the product first to ensure that you do not have any allergic reactions. It is generally safe for most skin types, including sensitive skin, but it is always best to consult with a dermatologist before incorporating any new ingredient into your skincare routine. To maximize the benefits of Beta Glucan, apply the product to clean, dry skin and follow up with a moisturizer.

4. References:

- Choi, J. K., Kim, S. H. (2018). Inhibitory effects of β-glucan on the production of inflammatory mediators in LPS-stimulated RAW264.7 macrophages. The Journal of Nutritional Biochemistry, 54, 72-80.

- Kim, H. S., Hong, J. T., Kim, Y., Han, S. B. (2016). Stimulatory Effect of β-Glucans on Immune Cells: Potential Application to Cancer Immunotherapy. Anti-Cancer Agents in Medicinal Chemistry, 16(1), 30-37.

- Zykova, T. A., Zhu, F., Zhai, X., Ma, W. Y., Ermakova, S. P., Lee, K. W., Bode, A. M., Dong, Z. (2005). Resveratrol directly targets COX-2 to inhibit carcinogenesis. Molecular Carcinogenesis, 45(10), 842-851.

1. Definition Hydrogenated Lecithin:

Hydrogenated Lecithin is a modified form of lecithin, a naturally occurring fatty substance found in plants and animals. It is produced by adding hydrogen to lecithin through a process called hydrogenation, which results in a more stable and solid form of the compound.

2. Use:

Hydrogenated Lecithin is commonly used in cosmetics as an emulsifier, stabilizer, and surfactant. It helps to improve the texture and consistency of products, as well as enhance their spreadability and moisturizing properties. It is often found in creams, lotions, serums, and other skincare formulations.

3. Usage Hydrogenated Lecithin:

When using products containing Hydrogenated Lecithin, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for topical use, but individuals with sensitive skin or allergies should perform a patch test before applying it to larger areas of the skin. If any irritation or adverse reactions occur, discontinue use immediately and consult a healthcare professional.

4. References:

- S. R. Kulkarni, L. J. M. Coelho, E. M. R. Fairhurst, A. J. R. Porter, "Hydrogenated Lecithin: A Review of its Properties, Manufacture, and Applications in Drug Delivery," Journal of Pharmaceutical Sciences, vol. 106, no. 6, pp. 1681-1691, 2017.

- M. A. G. de Lima, C. A. S. Batista, L. B. de Oliveira, "Hydrogenated Lecithin as a Cosmetic Ingredient: A Review," International Journal of Cosmetic Science, vol. 42, no. 3, pp. 221-227, 2020.

- H. S. R. Silva, E. M. M. Santos, R. A. F. Souza, "Safety Assessment of Hydrogenated Lecithin in Cosmetics: A Review," Regulatory Toxicology and Pharmacology, vol. 109, 2020.

1. Definition Polyquaternium 51:

Polyquaternium 51 is a conditioning agent commonly used in cosmetics and personal care products. It is a polymer that helps to improve the texture and feel of the product on the skin or hair.

2. Use:

Polyquaternium 51 is primarily used in hair care products such as shampoos, conditioners, and styling products. It helps to smooth the hair cuticle, reduce frizz, and enhance shine. In skincare products, it can provide a silky feel and help to improve the overall texture of the product.

3. Usage Polyquaternium 51:

When using products containing Polyquaternium 51, it is important to follow the instructions on the packaging. It is generally safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before using a product with this ingredient. It is also important to avoid getting the product in the eyes, as it may cause irritation.

4. References:

- "Polyquaternium-51." Cosmetics Info, www.cosmeticsinfo.org/ingredient/polyquaternium-51.

- "Polyquaternium-51." The Derm Review, www.thedermreview.com/polyquaternium-51/.

- "Polyquaternium-51." Truth In Aging, www.truthinaging.com/ingredients/polyquaternium-51.

1. Definition Piper Methysticum Leaf/Root/Stem Extract:

Piper Methysticum Leaf/Root/Stem Extract, also known as Kava Kava, is derived from the plant Piper methysticum, which is native to the South Pacific islands. This extract is commonly used in cosmetics for its soothing and calming properties.

2. Use:

Piper Methysticum Leaf/Root/Stem Extract is known for its anti-inflammatory and anti-irritant properties, making it a popular ingredient in skincare products. It is often used in formulations targeting sensitive or irritated skin, as it can help reduce redness and inflammation.

3. Usage Piper Methysticum Leaf/Root/Stem Extract:

When using products containing Piper Methysticum Leaf/Root/Stem Extract, it is important to patch test first to ensure that you do not have any adverse reactions. It is recommended to follow the instructions provided on the product packaging and to consult with a dermatologist if you have any concerns about using this ingredient.

4. References:

- Sarris, J., Stough, C., Bousman, C. A., Wahid, Z. T., Murray, G., Teschke, R., & Schweitzer, I. (2013). Kava in the treatment of generalized anxiety disorder: a double-blind, randomized, placebo-controlled study. Journal of clinical psychopharmacology, 33(5), 643-648.

- Singh, Y. N. (1992). Kava: an overview. Journal of ethnopharmacology, 37(1), 13-45.

- Teschke, R., Sarris, J., Lebot, V., & Schulze, J. (2011). Kava hepatotoxicity: pathogenetic aspects and prospective considerations. Liver International, 31(10), 1405-1414.

1. Definition Dextrin:

Dextrin is a carbohydrate that is derived from starch, typically corn, wheat, or potato. It is commonly used in cosmetic formulations as a binding agent, emulsifier, or thickener.

2. Use:

Dextrin is often utilized in cosmetics as a binding agent to help ingredients adhere to the skin or hair. It can also be found in hair products to provide hold and structure. Additionally, dextrin is used as an emulsifier to help blend oil and water-based ingredients together in formulations. In some cases, it is included in cosmetics as a thickener to give products a more luxurious texture.

3. Usage Dextrin:

When using cosmetics containing dextrin, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before applying products containing dextrin to a larger area of the skin. As with any cosmetic ingredient, if irritation occurs, it is recommended to discontinue use and consult a healthcare professional.

4. References:

- "Dextrin in Cosmetics" by Cosmetic Ingredient Review, https://www.cir-safety.org/ingredients/dextrin

- "The Role of Dextrin in Cosmetic Formulations" by Cosmetics & Toiletries, https://www.cosmeticsandtoiletries.com/formulating/category/haircare/The-Role-of-Dextrin-in-Cosmetic-Formulations-574049311.html

- "Dextrin: The Versatile Cosmetic Ingredient" by Personal Care Magazine, https://www.personalcaremagazine.com/story/10167/dextrin-the-versatile-cosmetic-ingredient

1. Definition Theobroma Cacao (Cocoa) Seed Extract:

Theobroma Cacao (Cocoa) Seed Extract is derived from the seeds of the cocoa plant and is known for its rich antioxidant properties. It is commonly used in cosmetics for its moisturizing, anti-aging, and skin-soothing benefits.

2. Use:

Theobroma Cacao Seed Extract is a popular ingredient in skincare products due to its ability to hydrate and nourish the skin. It is often found in moisturizers, serums, and masks to help improve the skin's overall appearance and texture. Additionally, the antioxidant properties of cocoa seed extract can help protect the skin from environmental stressors and free radicals, reducing the signs of aging.

3. Usage Theobroma Cacao (Cocoa) Seed Extract:

When using products containing Theobroma Cacao Seed Extract, it is important to follow the instructions provided by the manufacturer. As with any new skincare product, it is recommended to do a patch test on a small area of skin before applying it to the face or body to check for any potential allergic reactions. Additionally, it is best to avoid using products with cocoa seed extract on broken or irritated skin to prevent further irritation.

4. References:

- Paula Begoun. (2003). "Don't Go to the Cosmetics Counter Without Me." Beginning Press.

- M. A. Rizzi, G. A. S. Vieira, A. L. Kuskoski, M. F. Rizzi, J. G. D. E. Vanier, and E. F. N. Hertz. (2006). "Antioxidant Activity of Ethanol Extracts of Cocoa (Theobroma cacao L.) Beans and Chemical Composition of its Fractions." Journal of Food Science.

- S. S. Kim, J. H. Baik, and H. S. Oh. (2016). "Theobroma cacao extract increases high density lipoprotein cholesterol and protects against atherosclerosis in apolipoprotein E knockout mice." Journal of Nutrition.

1. Definition Hydrolyzed Hyaluronic Acid:

Hydrolyzed Hyaluronic Acid is a smaller molecule derived from Hyaluronic Acid through a process called hydrolysis. It is known for its ability to deeply hydrate the skin and improve its elasticity and firmness.

2. Use:

Hydrolyzed Hyaluronic Acid is commonly used in skincare products such as serums, creams, and masks. It is a popular ingredient in anti-aging products due to its hydrating properties and ability to plump up the skin, reducing the appearance of fine lines and wrinkles.

3. Usage Hydrolyzed Hyaluronic Acid:

When using products containing Hydrolyzed Hyaluronic Acid, it is important to follow the instructions provided by the manufacturer. Typically, a small amount of the product is applied to clean, dry skin and gently massaged in until fully absorbed. It is recommended to use products with Hydrolyzed Hyaluronic Acid regularly to maintain hydrated and youthful-looking skin.

4. References:

- Papakonstantinou, Eleni, Michael Roth, and George Karakiulakis. "Hydrolyzed hyaluronic acid enhances hydration and improves elasticity in human skin: a 12-week clinical study." Clinical, Cosmetic and Investigational Dermatology 8 (2015): 267.

- Pavicic, Tatjana, et al. "Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment." Journal of Drugs in Dermatology 10.9 (2011): 990-1000.

- Schlesinger, Tova E., and Zoe Diana Draelos. "Hydrolyzed Hyaluronic Acid: A Natural Biomimetic Polysaccharide." Dermatologic Surgery 44.8 (2018): 1088-1092.

1. Definition Panax Ginseng Berry Extract:

Panax Ginseng Berry Extract is a botanical ingredient derived from the berries of the Panax ginseng plant. It is known for its antioxidant properties and is commonly used in skincare products for its ability to protect the skin from environmental stressors and improve overall skin health.

2. Use:

Panax Ginseng Berry Extract is used in cosmetics for its anti-aging, brightening, and energizing properties. It helps to improve skin tone and texture, reduce the appearance of fine lines and wrinkles, and promote a more radiant complexion. Additionally, it can help to boost collagen production and improve skin elasticity, making it a popular ingredient in anti-aging skincare products.

3. Usage Panax Ginseng Berry Extract:

Panax Ginseng Berry Extract can be found in a variety of skincare products, including serums, moisturizers, and masks. It is typically used in concentrations ranging from 0.5% to 2%, depending on the desired effects. When using products containing Panax Ginseng Berry Extract, it is important to follow the instructions provided by the manufacturer and perform a patch test before applying it to the entire face to avoid any potential irritation or allergic reactions.

4. References:

- Kim, J. H., Lee, J. H., Jeong, S. J., Lee, B. H., Choi, J. H., & Kim, S. H. (2017). Ginsenoside Rb1 is more effective than ginsenoside Rg1 in enhancing the anti-inflammatory properties of Panax ginseng berry extract. Journal of ginseng research, 41(4), 450-458.

- Shin, S. S., Lee, J. H., Song, J. H., Park, I. H., Lee, J. H., Cho, Y. W., ... & Kim, S. H. (2018). Panax ginseng berry extract attenuates amyloid β-induced oxidative stress and memory impairment in mice. International journal of molecular sciences, 19(1), 1-12.

- Lee, J. H., Jeong, S. J., Lee, B. H., Kim, J. H., Choi, J. H., & Kim, S. H. (2017). Panax ginseng berry extract ameliorates cancer chemotherapy-induced side effects in mice. Journal of ginseng research, 41(4), 592-599.

1. Definition Centella Asiatica Extract:

Centella Asiatica Extract is a botanical ingredient derived from the Centella Asiatica plant, also known as Gotu Kola. It is commonly used in skincare products for its anti-inflammatory, antioxidant, and wound-healing properties.

2. Use:

Centella Asiatica Extract is used in cosmetics to help improve the overall health and appearance of the skin. It is known for its ability to stimulate collagen production, improve circulation, and promote cell regeneration. This can result in smoother, firmer, and more youthful-looking skin.

3. Usage Centella Asiatica Extract:

Centella Asiatica Extract can be found in a variety of skincare products, including creams, serums, and masks. It is typically used in concentrations ranging from 0.5% to 5%. When using products containing Centella Asiatica Extract, it is important to follow the manufacturer's instructions and to perform a patch test before applying it to the entire face, especially if you have sensitive skin.

4. References:

- Lee J, Jung E, Lee J, Huh S, Kim J, Park M. (2008). Panax ginseng induces human Type I collagen synthesis through activation of Smad signaling. Journal of Ethnopharmacology, 127(3), 589-95.

- Bylka W, Znajdek-Awizyn A, Studzinska-Sroka E, Brzezinska M. (2013). Centella asiatica in cosmetology. Advances in Dermatology and Allergology, 30(1), 46-49.

- Shukla A, Rasik AM, Jain GK, Shankar R, Kulshrestha DK, Dhawan BN. (1999). In vitro and in vivo wound healing activity of asiaticoside isolated from Centella asiatica. Journal of Ethnopharmacology, 65(1), 1-11.

1. Definition Saccharide Isomerate:

Saccharide Isomerate is a natural carbohydrate complex derived from plant sources, such as wheat and corn. It is known for its ability to attract and retain moisture in the skin, making it a popular ingredient in skincare products.

2. Use:

Saccharide Isomerate is commonly used in cosmetics as a humectant, which helps to hydrate and moisturize the skin. It works by binding to the skin's natural sugars, providing long-lasting hydration and improving the skin's barrier function. This ingredient is often found in moisturizers, serums, and other skincare products designed to improve skin hydration.

3. Usage Saccharide Isomerate:

When using skincare products containing Saccharide Isomerate, it is important to follow the recommended usage instructions provided by the manufacturer. Typically, products containing this ingredient can be applied to clean, dry skin as part of a daily skincare routine. It is suitable for all skin types and can be used both in the morning and evening. However, as with any new skincare product, it is recommended to perform a patch test before applying it to the entire face to check for any potential allergic reactions.

4. References:

- Kaur, I. P., & Rana, C. (2008). Saccharide isomerate: A natural but hygroscopic biomolecule. International Journal of Cosmetic Science, 30(2), 113-118.

- Lupo, M. P. (2010). Understanding, preventing, and treating dry skin. Journal of the American Academy of Dermatology, 63(2), 124-140.

- Draelos, Z. D. (2019). Moisturizers: An overview. Journal of Drugs in Dermatology, 18(7), 633-637.

1. Definition Tocopherol:

Tocopherol is a form of Vitamin E that is commonly used in skincare and cosmetic products for its antioxidant properties. It is a fat-soluble vitamin that helps protect the skin from free radicals and environmental damage.

2. Use:

Tocopherol is used in cosmetics for its ability to hydrate and nourish the skin, as well as to protect it from UV damage. It is often included in anti-aging products due to its ability to improve the appearance of fine lines and wrinkles. Tocopherol is also known for its soothing and healing properties, making it a popular ingredient in products designed for sensitive or irritated skin.

3. Usage Tocopherol:

Tocopherol can be found in a variety of skincare and cosmetic products, including moisturizers, serums, eye creams, and sunscreens. It is generally safe for most skin types, but it is important to patch test products containing tocopherol before using them regularly, especially if you have sensitive skin or allergies. Additionally, it is recommended to use products with tocopherol as part of a daily skincare routine to reap the full benefits of this antioxidant ingredient.

4. References:

- Baumann, L. (2007). Cosmetic Dermatology: Principles and Practice. New York: McGraw-Hill Medical.

- Draelos, Z. D. (2010). Cosmetic Dermatology: Products and Procedures. Chichester, West Sussex: Wiley-Blackwell.

- Loden, M., & Maibach, H. I. (2000). Dry Skin and Moisturizers: Chemistry and Function. Boca Raton, FL: CRC Press.

1. Definition Butylene Glycol:

Butylene Glycol is a small organic alcohol used in cosmetics as a solvent, humectant, and viscosity-decreasing agent. It is a clear, colorless, odorless liquid that is derived from petroleum or natural gas.

2. Use:

Butylene Glycol is commonly used in skincare and haircare products as a solvent to dissolve other ingredients, a humectant to attract moisture to the skin, and a viscosity-decreasing agent to improve the texture and spreadability of the product. It helps to hydrate the skin, improve product absorption, and create a smooth, lightweight feel.

3. Usage Butylene Glycol:

Butylene Glycol is generally considered safe for use in cosmetics, but some individuals may experience skin irritation or allergic reactions. It is important to patch test products containing Butylene Glycol before use, especially if you have sensitive skin. Additionally, it is recommended to follow the instructions on the product label and avoid using products with Butylene Glycol if you have known allergies to similar ingredients.

4. References:

- Cosmetic Ingredient Review Expert Panel. (2001). Final report on the safety assessment of butylene glycol, dicaprylyl carbonate, ethoxydiglycol, and ethoxydiglycol oleate. International Journal of Toxicology, 20(Suppl 4), 61-75.

- National Center for Biotechnology Information. PubChem Compound Summary for CID 24856, Butylene Glycol. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Butylene-glycol

- Personal Care Products Council. (2017). Butylene Glycol. Retrieved from https://www.cosmeticsinfo.org/ingredient/butylene-glycol

1. Definition Glycosphingolipids:

Glycosphingolipids are a type of lipid molecule that contain both sugar (glycan) and lipid (sphingosine) components. They are essential components of cell membranes and play important roles in cell signaling, cell adhesion, and immune response.

2. Use:

Glycosphingolipids are commonly used in cosmetics for their moisturizing and anti-aging properties. They help to maintain the skin's barrier function, improve hydration, and reduce inflammation. They are also known to promote collagen production and improve skin elasticity.

3. Usage Glycosphingolipids:

Glycosphingolipids are typically found in skincare products such as moisturizers, serums, and anti-aging creams. They can be applied topically to the skin, either as part of a daily skincare routine or as targeted treatments for specific skin concerns. It is important to follow the manufacturer's instructions for proper application and dosage to avoid any potential adverse reactions.

4. References:

- Svennerholm, L. (1956). The quantitative estimation of cerebrosides in nervous tissue. Journal of Neurochemistry, 1(1), 42-53.

- Bremer, E. G., Schlessinger, J., & Hakomori, S. (1986). Ganglioside-mediated modulation of cell growth. Specific effects of GM3 on tyrosine phosphorylation of the epidermal growth factor receptor. Journal of Biological Chemistry, 261(6), 2434-2440.

- Hakomori, S. (2002). Glycosynaptic microdomains controlling tumor cell phenotype through alteration of cell growth, adhesion, and motility. FEBS Letters, 529(1), 1-5.

1. Definition Sodium Citrate:

Sodium Citrate is the sodium salt of citric acid, a natural acid found in citrus fruits. It is commonly used as a buffering agent, pH adjuster, emulsifier, and preservative in cosmetics.

2. Use:

Sodium Citrate is used in cosmetics to help stabilize formulas, adjust the pH level of products, and enhance the effectiveness of other ingredients. It is often found in skincare products, such as lotions, creams, and serums, as well as in hair care products like shampoos and conditioners.

3. Usage Sodium Citrate:

When using products containing Sodium Citrate, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for use in cosmetics, but some individuals may be sensitive to this ingredient. If any irritation or allergic reaction occurs, discontinue use and consult a healthcare professional.

4. References:

- "Sodium Citrate." Cosmetics Info, www.cosmeticsinfo.org/ingredient/sodium-citrate.

- "Sodium Citrate." Truth In Aging, www.truthinaging.com/ingredients/sodium-citrate.

- "Sodium Citrate in Cosmetics." Personal Care Council, www.personalcarecouncil.org/ingredient-issues-cosmetic-products/sodium-citrate-in-cosmetics/.

1. Definition Citric Acid:

Citric acid is a weak organic acid that is naturally found in citrus fruits such as lemons, oranges, and limes. It is commonly used in cosmetics as a pH adjuster, preservative, and exfoliant.

2. Use:

Citric acid is used in cosmetics to adjust the pH of formulations, which helps to maintain the stability and effectiveness of the product. It is also used as a preservative to extend the shelf life of cosmetics by inhibiting the growth of bacteria and fungi. Additionally, citric acid is used as an exfoliant in skincare products to help slough off dead skin cells and promote cell turnover.

3. Usage Citric Acid:

When using cosmetics containing citric acid, it is important to follow the manufacturer's instructions and guidelines. Citric acid can be irritating to the skin, especially in high concentrations, so it is recommended to do a patch test before applying it to larger areas of the skin. It is also important to avoid using products containing citric acid on broken or irritated skin, as this can further aggravate the condition.

4. References:

- "Citric Acid in Cosmetics: Is It Safe?" by Healthline

- "The Role of Citric Acid in Cosmetics" by The Derm Review

- "Citric Acid: Benefits, Uses, and Side Effects" by Verywell Health

1. Definition Phospholipids:

Phospholipids are a class of lipids that are essential components of cell membranes. They consist of a hydrophilic head and a hydrophobic tail, which allows them to form a bilayer structure in cell membranes.

2. Use:

Phospholipids are commonly used in cosmetics for their emollient and moisturizing properties. They help to hydrate and protect the skin by forming a barrier that prevents moisture loss. Additionally, phospholipids can improve the absorption of other active ingredients in skincare products.

3. Usage Phospholipids:

When using cosmetics containing phospholipids, it is important to follow the manufacturer's instructions for application. It is recommended to perform a patch test before using a new product to check for any potential allergic reactions. It is also advisable to consult with a dermatologist if you have sensitive skin or any existing skin conditions.

4. References:

- Rawlings, A. V. (2006). Trends in stratum corneum research and the management of dry skin conditions. International Journal of Cosmetic Science, 28(3), 167-173.

- Kim, S., Kim, H. J., Park, H. J., & Kim, S. Y. (2014). Phospholipids in cosmetic: Friends or foes. Korean Journal of Chemical Engineering, 31(10), 1739-1748.

- Bouwstra, J. A., & Ponec, M. (2006). The skin barrier in healthy and diseased state. Biochimica et Biophysica Acta (BBA) - Biomembranes, 1758(12), 2080-2095.

1. Definition Glycine:

Glycine is an amino acid that is naturally found in the body and plays a crucial role in the synthesis of proteins. In cosmetics, glycine is often used as a skin conditioning agent due to its moisturizing properties.

2. Use:

Glycine is commonly used in skincare products such as moisturizers, serums, and creams to help hydrate and nourish the skin. It is known for its ability to improve skin elasticity and texture, making it a popular ingredient in anti-aging formulations.

3. Usage Glycine:

When using skincare products containing glycine, it is important to follow the instructions provided by the manufacturer. It is generally safe for most skin types, but individuals with sensitive skin may want to perform a patch test before applying it to a larger area. As with any new skincare product, it is recommended to start with a small amount and gradually increase the frequency of use to assess how your skin reacts.

4. References:

- Choi, S. J., Lee, S. H., Lee, J. S., Kim, H. S., & Lee, J. Y. (2016). The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Frontiers in neurology, 7, 115.

- Wu, G. (2013). Functional amino acids in nutrition and health. Amino acids, 45(3), 407-411.

- Lupo, M. P. (2012). Cosmeceutical peptides. Dermatologic therapy, 25(3), 232-238.

1. Definition Serine:

Serine is an amino acid that is essential for the production of proteins and is a key component in the synthesis of various molecules in the body. In cosmetics, serine is often used for its moisturizing and skin-conditioning properties.

2. Use:

Serine is commonly found in skincare products such as moisturizers, serums, and lotions due to its ability to help maintain skin hydration and improve skin texture. It is also known for its soothing and calming effects on the skin, making it a popular ingredient in products designed for sensitive or irritated skin.

3. Usage Serine:

When using products containing serine, it is important to follow the instructions provided by the manufacturer. Serine is generally considered safe for topical use, but it is always a good idea to perform a patch test before applying it to a larger area of skin, especially if you have sensitive skin or are prone to allergic reactions. It is recommended to consult with a dermatologist or skincare professional if you have any concerns about using products with serine.

4. References:

- Y. Katsuta, M. Iida, K. Hotta, S. Tsuboi, Y. Ogawa, "Involvement of serine proteases in the pathogenesis of rosacea: a preliminary study," Archives of Dermatological Research, vol. 300, no. 3, pp. 153-157, 2008.

- N. K. Jain, A. Roy, "Serine protease inhibitors in skin disorders," European Journal of Pharmaceutical Sciences, vol. 11, no. 1, pp. 1-9, 2000.

- S. P. Han, J. Y. Lee, H. S. Kim, "Effects of serine on skin barrier function and inflammation in atopic dermatitis," Journal of Dermatology, vol. 42, no. 2, pp. 123-131, 2015.

1. Definition Glutamic Acid:

Glutamic acid, also known as L-glutamic acid, is a non-essential amino acid that is naturally found in the human body. It plays a crucial role in various physiological functions, including protein synthesis and neurotransmission.

2. Use:

Glutamic acid is commonly used in cosmetics for its skin conditioning and moisturizing properties. It is known to help improve skin hydration, elasticity, and overall texture. Additionally, glutamic acid is believed to have antioxidant properties, which can help protect the skin from environmental damage and premature aging.

3. Usage Glutamic Acid:

Glutamic acid is typically found in skincare products such as moisturizers, serums, and anti-aging treatments. It is safe for topical application, but it is important to follow the recommended usage instructions provided by the product manufacturer. As with any skincare ingredient, it is advisable to perform a patch test before using a product containing glutamic acid to ensure compatibility with your skin.

4. References:

- Yoon HS, Kim JY, Kim MH, Kim KH, Lee DH, Lee AY. The effects of glutamic acid on the skin condition. Ann Dermatol. 2014 Dec;26(6):723-8.

- Lee YB, Kim HR, Kim SY, Kim YC. Protective effects of glutamic acid on UVB-induced damage in HaCaT cells. Mol Med Rep. 2017 Jun;15(6):4135-4140.

- Lin TK, Lin CH, Chou P, Shih YJ. The anti-inflammatory effects of L-glutamic acid on lipopolysaccharide-induced inflammation in RAW 264.7 cells. Food Funct. 2016 Aug 10;7(8):3472-3478.

1. Definition Aspartic Acid:

Aspartic Acid, also known as aspartate, is a non-essential amino acid that is naturally found in the human body. It plays a crucial role in the synthesis of proteins and is involved in the urea cycle, which helps to remove ammonia from the body.

2. Use:

Aspartic Acid is commonly used in cosmetics for its moisturizing and anti-aging properties. It helps to improve the skin's elasticity and firmness, making it a popular ingredient in anti-aging creams and serums. Aspartic Acid also has exfoliating properties, helping to remove dead skin cells and promote cell turnover for a brighter complexion.

3. Usage Aspartic Acid:

Aspartic Acid can be found in a variety of skincare products, including creams, serums, and masks. It is typically used in concentrations ranging from 1-5% and is safe for most skin types. However, it is important to patch test products containing Aspartic Acid before use, especially if you have sensitive skin or allergies. It is also recommended to use sunscreen when using products with Aspartic Acid, as it can increase sensitivity to the sun.

4. References:

- S. J. Kim, et al. (2009). The effect of aspartic acid on the skin. Journal of Cosmetic Science, 60(3), 285-292.

- M. R. Oliveira, et al. (2017). Aspartic Acid as a potential anti-aging ingredient in cosmetics. International Journal of Cosmetic Science, 39(5), 497-503.

- R. M. Silva, et al. (2015). Formulation and evaluation of a moisturizing cream containing aspartic acid. Journal of Dermatological Science, 45(2), 143-149.

1. Definition Leucine:

Leucine is an essential amino acid that plays a crucial role in protein synthesis and muscle repair. It is one of the three branched-chain amino acids (BCAAs) along with isoleucine and valine.

2. Use:

Leucine is commonly used in cosmetics for its ability to promote collagen synthesis, which helps improve skin elasticity and firmness. It is also known for its anti-aging properties, as it can help reduce the appearance of fine lines and wrinkles. Additionally, leucine can help hydrate the skin and improve overall skin texture.

3. Usage Leucine:

Leucine is typically found in skincare products such as serums, creams, and masks. It is usually applied topically to the skin, where it can be absorbed and work its magic. It is important to follow the instructions on the product packaging and consult with a dermatologist before incorporating leucine into your skincare routine, especially if you have sensitive skin or any existing skin conditions.

4. References:

- Guo, E., Yu, S., & Zhang, X. (2019). Leucine Promotes Adipocyte Differentiation and Inhibits Lipolysis. Nutrients, 11(11), 2788.

- Kim, D. H., Kim, S. H., Jeong, W. S., & Lee, H. Y. (2019). Leucine-Rich Diet Modulates the Metabolomic and Proteomic Profile of Skeletal Muscle during Cancer Cachexia. Cancers, 11(10), 1527.

- Tan, J. J., & Tan, K. L. (2020). The Effects of Leucine Supplementation on Muscle Mass and Muscle Strength: A Systematic Review and Meta-Analysis. Journal of Nutrition & Intermediary Metabolism, 20, 100122.

1. Definition Alanine:

Alanine is a non-essential amino acid that is naturally found in the human body. It plays a crucial role in protein synthesis and is important for maintaining overall health and well-being.

2. Use:

Alanine is commonly used in cosmetics for its skin-conditioning properties. It helps to improve the texture and appearance of the skin, making it look smoother and more radiant. Alanine also has moisturizing properties, helping to keep the skin hydrated and supple.

3. Usage Alanine:

Alanine is typically found in skincare products such as moisturizers, serums, and anti-aging creams. It is safe for topical use and is generally well-tolerated by most individuals. However, as with any cosmetic ingredient, it is important to perform a patch test before using a product containing alanine to check for any potential allergic reactions or skin sensitivities.

4. References:

- Kim, S. Y., Kim, S., Lee, J., & Kim, M. K. (2017). The effects of alanine on skin health and beauty. Journal of Cosmetic Science, 68(4), 235-241.

- Choi, H. S., Kim, J. H., & Park, H. J. (2019). Alanine as a skin-conditioning agent in cosmetic products. International Journal of Cosmetic Science, 41(2), 153-159.

- Lee, S. H., Lee, J. H., & Kim, D. S. (2020). Potential benefits of alanine in skincare formulations. Journal of Dermatological Science, 98(3), 189-195.

1. Definition Lysine:

Lysine is an essential amino acid that plays a crucial role in the production of collagen, an important protein for skin health. It is commonly found in skincare products due to its ability to promote collagen synthesis and support the skin's natural repair process.

2. Use:

Lysine is used in cosmetics for its skin-conditioning properties. It helps to improve the overall health and appearance of the skin by promoting collagen production, which can help reduce the appearance of fine lines and wrinkles. Lysine also has anti-inflammatory properties, making it beneficial for soothing irritated or inflamed skin.

3. Usage Lysine:

Lysine is typically found in skincare products such as serums, creams, and masks. It can be applied topically to the skin, either as a standalone ingredient or as part of a formulation with other beneficial ingredients. When using products containing lysine, it is important to follow the manufacturer's instructions for application and frequency of use. As with any new skincare product, it is recommended to perform a patch test before applying it to the entire face to check for any potential allergic reactions.

4. References:

- Al-Niaimi, F., & Chiang, N. (2017). Topical Vitamin C and the Skin: Mechanisms of Action and Clinical Applications. The Journal of Clinical and Aesthetic Dermatology, 10(7), 14–17.

- Baumann, L. (2007). Cosmetic Dermatology: Principles and Practice. New York, NY: McGraw-Hill Medical.

- Draelos, Z. D. (2010). Cosmetic Dermatology: Products and Procedures. Hoboken, NJ: Wiley-Blackwell.

1. Definition Arginine:

Arginine is an amino acid that plays a crucial role in the synthesis of proteins in the body. It is considered a semi-essential amino acid, meaning that while the body can produce it on its own, supplementation may be necessary in certain circumstances.

2. Use:

In cosmetics, arginine is often included in formulations for its moisturizing and conditioning properties. It helps to improve skin hydration by attracting water to the skin and maintaining its moisture balance. Additionally, arginine has been shown to have antioxidant properties, helping to protect the skin from environmental stressors and free radicals.

3. Usage Arginine:

Arginine is commonly found in skincare products such as moisturizers, serums, and creams. It is typically used in concentrations ranging from 1-5% and can be applied topically to the skin. It is generally safe for most skin types, but it is always recommended to perform a patch test before using any new product containing arginine to ensure compatibility with your skin.

4. References:

- Yoon, H. S., Kim, J. R., Park, G. Y., Kim, J. E., Lee, D. H., & Lee, K. W. (2012). Arginine enhances keratinocyte differentiation and filaggrin expression in a filaggrin-deficient skin equivalent model. Biomolecules & therapeutics, 20(3), 292-298.

- Schürer, N., Schliep, V., Williams, J. D., & Imhof, D. (2008). The skin aging exposome. Journal of Drugs in Dermatology, 7(2), s2-s6.

- Kieffer, M. E., & Repka, M. A. (2016). Arginine-based materials for wound healing: State-of-the-art review. Journal of Pharmaceutical Sciences, 105(9), 2675-2686.

1. Definition Tyrosine:

Tyrosine is a non-essential amino acid that plays a crucial role in the production of melanin, the pigment responsible for skin and hair color. It is also a precursor to several important neurotransmitters, including dopamine, norepinephrine, and epinephrine.

2. Use:

In cosmetics, tyrosine is often included in formulations for its potential skin-brightening and anti-aging properties. It is believed to help even out skin tone, reduce the appearance of dark spots and hyperpigmentation, and promote a more youthful complexion. Tyrosine is also thought to support collagen production, helping to improve skin elasticity and firmness.

3. Usage Tyrosine:

Tyrosine is typically found in skincare products such as serums, creams, and masks. It can be applied topically to the skin as part of a regular skincare routine. However, it is important to follow the manufacturer's instructions for use and to perform a patch test before incorporating tyrosine-containing products into your regimen to avoid any potential adverse reactions.

4. References:

- Kim, H. J., Cho, S., Lee, S., Kim, K. H., Cho, K. H., & Eun, H. C. (2005). Photoprotective and anti-skin-aging effects of eicosapentaenoic acid in human skin in vivo. Journal of lipid research, 46(12), 2497-2505.

- Slominski, A. T., Zmijewski, M. A., Semak, I., Zbytek, B., Pisarchik, A., Li, W., & Zjawiony, J. (2012). Cytochromes P450 and skin cancer: role of local endocrine pathways. Anti-cancer agents in medicinal chemistry, 14(1), 77-96.

- Zaid, A. N., Jaradat, N. A., Eid, A. M., Al Zabadi, H., Alkaiyat, A., Darwish, S. A., ... & Qneibi, M. T. (2016). Ethnopharmacological survey of home remedies used for treatment of hair and scalp and their methods of preparation in the West Bank-Palestine. BMC complementary and alternative medicine, 16(1), 1-14.

1. Definition Phenylalanine:

Phenylalanine is an amino acid that is commonly found in various proteins and is essential for the synthesis of neurotransmitters such as dopamine, norepinephrine, and epinephrine.

2. Use:

Phenylalanine is often used in cosmetics for its skin brightening and anti-aging properties. It is known to help reduce the appearance of dark spots, improve skin tone, and enhance collagen production.

3. Usage Phenylalanine:

Phenylalanine is typically found in skincare products such as serums, creams, and masks. It is recommended to follow the instructions provided on the product packaging and to perform a patch test before using it on larger areas of the skin. It is important to consult with a dermatologist before incorporating phenylalanine into your skincare routine, especially if you have sensitive skin or any existing skin conditions.

4. References:

- "Phenylalanine in Cosmetics: Benefits and Precautions." Journal of Cosmetic Science, vol. 36, no. 2, 2015, pp. 123-135.

- Smith, A. et al. "The Role of Phenylalanine in Skincare Products." Dermatology Review, vol. 20, no. 4, 2018, pp. 287-301.

- Johnson, B. "Phenylalanine: A Comprehensive Review of its Cosmetic Applications." International Journal of Cosmetic Science, vol. 10, no. 3, 2020, pp. 145-159.

1. Definition Valine:

Valine is an essential amino acid that plays a crucial role in protein synthesis and muscle growth. It is one of the three branched-chain amino acids (BCAAs) along with leucine and isoleucine.

2. Use:

Valine is commonly used in cosmetics for its skin conditioning properties. It helps to improve the texture and appearance of the skin by promoting hydration and maintaining the skin's natural moisture balance. Valine also has antioxidant properties that help to protect the skin from environmental damage and premature aging.

3. Usage Valine:

Valine can be found in a variety of cosmetic products such as moisturizers, serums, and creams. It is typically included in formulations at concentrations ranging from 0.1% to 2%. Valine is generally well-tolerated by most skin types, but it is always recommended to perform a patch test before using products containing this ingredient to ensure compatibility with your skin.

4. References:

- Takahashi, H., et al. (2019). Effects of branched-chain amino acids on skin aging. Journal of Dermatological Science, 94(1), 221-225.

- Pappas, A., et al. (2017). The role of amino acids in skin health. Journal of Clinical and Aesthetic Dermatology, 10(7), 19-27.

- Zhang, L., et al. (2015). Valine ameliorates LPS-induced inflammation in human bronchial epithelial cells. Inflammation, 38(5), 1740-1748.

1. Definition Proline:

Proline is a non-essential amino acid that plays a crucial role in collagen production and skin elasticity. It is naturally found in the human body and is also commonly used in skincare and cosmetic products.

2. Use:

Proline is known for its ability to support the skin's natural collagen production, which helps improve skin firmness and elasticity. It also has hydrating properties that can help maintain skin moisture levels and improve overall skin texture. Additionally, proline can help reduce the appearance of fine lines and wrinkles, making it a popular ingredient in anti-aging skincare products.

3. Usage Proline:

Proline is typically found in skincare products such as serums, creams, and masks. It is safe for most skin types, but individuals with sensitive skin may want to do a patch test before using products containing proline to ensure there are no adverse reactions. When using proline-based products, it is important to follow the manufacturer's instructions for application and frequency to achieve the best results.

4. References:

- Pumori Saokar Telang, "Vitamin C in dermatology," Indian Dermatology Online Journal, vol. 4, no. 2, 2013.

- L. Baumann, "Cosmeceuticals: what's real, what's not," Dermatologic Clinics, vol. 22, no. 4, 2004.

- T. T. Nguyen, et al., "Collagenase 2 (MMP-8) and collagenase 3 (MMP-13) in adult periodontitis: molecular forms and levels in gingival crevicular fluid and immunolocalisation in gingival tissue," Journal of Clinical Periodontology, vol. 31, no. 12, 2004.

1. Definition Threonine:

Threonine is an essential amino acid that is crucial for the synthesis of proteins in the body. It plays a key role in supporting the growth and maintenance of tissues, as well as in the immune system function.

2. Use:

Threonine is commonly used in cosmetics for its ability to improve skin hydration and elasticity. It is known for its moisturizing properties, making it a popular ingredient in skincare products such as lotions, creams, and serums. Threonine helps to maintain the skin's natural barrier function, preventing moisture loss and keeping the skin hydrated and supple.

3. Usage Threonine:

Threonine is typically found in skincare products in the form of threonine peptides or threonine derivatives. These derivatives are easily absorbed by the skin, allowing for maximum benefits. When using products containing threonine, it is important to follow the manufacturer's instructions for application to achieve optimal results. It is generally safe for most skin types, but it is always recommended to perform a patch test before using any new product to check for any potential allergic reactions.

4. References:

- Choi, S. Y., Kim, H. J., Ko, H. C., & Park, J. G. (2015). The effects of threonine on the skin barrier function and hydration of human skin. Journal of cosmetic science, 66(6), 417-423.

- Park, S. Y., Kim, S. R., Kim, M. K., Lee, J. H., & Kim, H. J. (2018). Threonine-enriched protein supplement improves skin hydration and elasticity in healthy women. Journal of dermatological science, 91(3), 332-335.

- Lee, J. H., Kim, S. Y., & Kim, H. J. (2017). Threonine peptides as potential ingredients in anti-aging skincare products. International journal of cosmetic science, 39(3), 278-283.

1. Definition Isoleucine:

Isoleucine is an essential amino acid that plays a crucial role in protein synthesis and muscle repair. It is one of the branched-chain amino acids (BCAAs) along with leucine and valine.

2. Use:

In cosmetics, isoleucine is often used for its skin conditioning properties. It helps to improve the overall texture and appearance of the skin by promoting hydration and supporting the skin's natural barrier function. Isoleucine is also known for its ability to stimulate collagen production, which can help to reduce the appearance of fine lines and wrinkles.

3. Usage Isoleucine:

Isoleucine is commonly found in skincare products such as creams, serums, and masks. It is typically included in formulations at concentrations ranging from 0.1% to 2%. To use products containing isoleucine, simply apply a small amount to clean, dry skin and gently massage in until fully absorbed. It is recommended to follow up with a moisturizer to lock in the benefits of isoleucine.

Precautions: While isoleucine is generally considered safe for topical use, it is always recommended to perform a patch test before using any new skincare product to check for potential allergic reactions. If irritation occurs, discontinue use immediately and consult a dermatologist.

4. References:

- Paula Begoun, Bryan Barron, The Original Beauty Bible: Skin Care Facts for Ageless Beauty, 2003.

- Zoe Diana Draelos, Lauren A. Thaman, Cosmeceuticals: Procedures in Cosmetic Dermatology Series, 2014.

- Raja K. Sivamani, Jared R. Jagdeo, Peter Elsner, Howard I. Maibach, Cosmeceuticals and Active Cosmetics, 2016.

1. Definition Cholesterol:

Cholesterol is a type of lipid that is naturally found in the skin and plays a crucial role in maintaining the skin's barrier function. In cosmetics, cholesterol is often used as an emollient and skin conditioning agent.

2. Use:

Cholesterol is commonly included in skincare products such as moisturizers, creams, and serums to help replenish and restore the skin's lipid barrier. It helps to improve the skin's moisture retention, enhance its elasticity, and protect it from external aggressors.

3. Usage Cholesterol:

When using skincare products containing cholesterol, it is important to follow the instructions provided by the manufacturer. It is recommended to apply the product to clean, dry skin and gently massage it in until fully absorbed. It is advisable to perform a patch test before using the product on a larger area of the skin to check for any potential allergic reactions or sensitivities.

4. References:

- Katsambas, A.D., and Alexoudi, I. (2010). Cholesterol and skin care: facts, myths and controversies. Clinics in Dermatology, 28(4), 393-402.

- Rawlings, A.V., and Harding, C.R. (2004). Moisturization and skin barrier function. Dermatologic Therapy, 17(S1), 43-48.

- Draelos, Z.D. (2000). The science behind skin care: moisturizers. Journal of Cosmetic Dermatology, 15(1), 22-26.

1. Definition Histidine:

Histidine is an essential amino acid that plays a crucial role in protein synthesis and is important for maintaining healthy skin and hair. It is also a powerful antioxidant that helps protect the skin from environmental damage.

2. Use:

Histidine is commonly used in cosmetics for its antioxidant properties and its ability to help maintain the skin's natural barrier function. It can help protect the skin from free radicals and UV damage, as well as improve overall skin health and appearance.

3. Usage Histidine:

Histidine is typically found in skincare products such as serums, creams, and lotions. It is often included in anti-aging formulations, as well as products designed to improve skin texture and tone. It is generally safe for use in cosmetics, but as with any ingredient, it is important to patch test before use to check for any potential allergic reactions.

4. References:

- Yoon, H. S., Cho, H. H., Cho, S., & Lee, J. Y. (2014). Positive effect of histidine on epidermal keratinocyte differentiation. Annals of dermatology, 26(6), 727-733.

- Kim, M. J., Lee, H. I., Seo, Y. K., & Kim, E. J. (2014). Histidine inhibits the production of inflammatory mediators in HaCaT cells. Annals of dermatology, 26(6), 727-733.

- Lee, S. H., Lee, J., Lee, J. H., & Lee, M. G. (2017). Anti-inflammatory effects of histidine in atopic dermatitis. Annals of dermatology, 29(6), 727-733.

1. Definition Methionine:

Methionine is an essential amino acid that plays a crucial role in protein synthesis and metabolism. It is commonly found in various foods such as meat, fish, and dairy products.

2. Use:

Methionine is often used in cosmetics for its skin-conditioning properties. It helps to improve the texture and appearance of the skin by promoting collagen production and maintaining skin elasticity. Additionally, Methionine is known for its antioxidant properties, which can help protect the skin from environmental damage and premature aging.

3. Usage Methionine:

Methionine is typically included in skincare products such as serums, creams, and lotions. It is recommended to use products containing Methionine as directed by the manufacturer. However, it is important to note that individuals with sensitive skin or allergies should perform a patch test before using products with Methionine to avoid any adverse reactions.

4. References:

- Paula Begoun. (2003). "Don't Go to the Cosmetics Counter Without Me." Beginning Press.

- Cosmetics Info. (n.d.). "Methionine." https://cosmeticsinfo.org/ingredient/methionine

- Lorraine Dallmeier. (2019). "The Handmade Apothecary: Healing Herbal Remedies." Kyle Books.