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 Larix Europaea Wood Extract:

Larix Europaea Wood Extract is an extract derived from the wood of the European Larch tree (Larix Europaea). It is rich in antioxidants, vitamins, and minerals that provide various benefits for the skin.

2. Use:

Larix Europaea Wood Extract is commonly used in cosmetics for its anti-inflammatory, antioxidant, and anti-aging properties. It helps to protect the skin from environmental stressors, reduce the appearance of fine lines and wrinkles, and promote a more youthful complexion.

3. Usage Larix Europaea Wood Extract:

Larix Europaea Wood 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 active ingredients for enhanced benefits. It is suitable for all skin types and can be used daily as part of a skincare routine.

4. References:

- Hwang E, Ngo HTT, Park B, Seo SA, Yang JE, Yi TH. Larix kaempferi bark extract inhibits adipogenesis in 3T3-L1 cells and fat accumulation in high-fat diet-induced obese mice. Nutrients. 2017;9(9):1036. doi:10.3390/nu9091036

- Kim YR, Park BC, Park SY, Park JH, Jung IC, You YO. The anti-inflammatory effect of larch wood extract via nuclear factor-κB in human umbilical vein endothelial cells. Biol Pharm Bull. 2017;40(11):1906-1912. doi:10.1248/bpb.b17-00417

- Kim YR, Park BC, Park SY, Park JH, Jung IC, You YO. The anti-inflammatory effect of larch wood extract via nuclear factor-κB in human umbilical vein endothelial cells. Biol Pharm Bull. 2017;40(11):1906-1912. doi:10.1248/bpb.b17-00417

1. Definition Zinc Chloride:

Zinc Chloride is a chemical compound with the formula ZnCl2. It is a white crystalline solid that is highly soluble in water. In cosmetics, Zinc Chloride is commonly used as a denaturant, astringent, and antimicrobial agent.

2. Use:

Zinc Chloride is used in cosmetics for its astringent properties, which help to tighten and tone the skin. It is also used as a denaturant in products such as hair dyes and nail polishes to prevent ingestion. Additionally, Zinc Chloride acts as an antimicrobial agent, helping to prevent the growth of bacteria and fungi in cosmetic formulations.

3. Usage Zinc Chloride:

When using Zinc Chloride in cosmetics, it is important to follow the recommended guidelines for concentration and application. Overuse of Zinc Chloride can lead to skin irritation and dryness. It is also important to avoid contact with eyes and mucous membranes, as Zinc Chloride can cause irritation in these areas. It is recommended to perform a patch test before using products containing Zinc Chloride to check for any potential allergic reactions.

4. References:

- "Zinc Chloride." Cosmeticsinfo.org, www.cosmeticsinfo.org/ingredient/zinc-chloride.

- "Zinc Chloride." The Dermatology Review, www.thedermreview.com/zinc-chloride/.

- "Zinc Chloride: Uses, Side Effects, Interactions, Dosage, and Warning." WebMD, www.webmd.com/vitamins/ai/ingredientmono-982/zinc-chloride.

1. Definition Camellia Sinensis Leaf Extract:

Camellia Sinensis Leaf Extract is derived from the leaves of the Camellia Sinensis plant, which is the same plant used to produce green, black, white, and oolong teas. This extract is rich in antioxidants, vitamins, and minerals that have numerous benefits for the skin.

2. Use:

Camellia Sinensis Leaf Extract is commonly used in skincare products for its antioxidant properties. It helps to protect the skin from environmental damage, such as UV rays and pollution, and can also help to reduce inflammation and promote overall skin health. Additionally, this extract has a soothing effect on the skin and can help to improve the appearance of fine lines and wrinkles.

3. Usage Camellia Sinensis Leaf Extract:

Camellia Sinensis Leaf Extract can be found in a variety of skincare products, including serums, moisturizers, and masks. It is generally safe for all skin types, but it is always recommended to do a patch test before using a new product to ensure that you do not have any adverse reactions. When using products containing Camellia Sinensis Leaf Extract, it is important to follow the instructions provided by the manufacturer for best results.

4. References:

- Baek, J. H., Kim, S. M., Lee, H., Lee, J. Y., & Kim, J. H. (2016). Green tea extract and its major component epigallocatechin gallate inhibits melanoma cell growth in vitro and in vivo. Food and chemical toxicology, 87, 1-11.

- Yoon, J. H., Baek, S. J., & Lee, S. H. (2012). Anti-inflammatory effects of green tea catechin on atherosclerosis by regulating NF-κB signaling pathway. Nutrition research and practice, 6(4), 294-301.

- Hsu, S. (2005). Green tea and the skin. Journal of the American Academy of Dermatology, 52(6), 1049-1059.

1. Definition Vitis Vinifera (Grape):

Vitis Vinifera, commonly known as grape, is a species of grapevine native to the Mediterranean region. It is widely cultivated for its fruit, which is used to make wine, grape juice, and raisins. Grape seed extract and grape seed oil are also derived from Vitis Vinifera and are known for their potential health and skincare benefits.

2. Use:

Vitis Vinifera is used in cosmetics for its antioxidant properties. Grape seed extract is rich in proanthocyanidins, which are powerful antioxidants that help protect the skin from free radical damage and premature aging. It is also known to have anti-inflammatory and anti-microbial properties, making it beneficial for treating acne and other skin conditions. Grape seed oil is lightweight and easily absorbed by the skin, making it a popular ingredient in moisturizers, serums, and other skincare products.

3. Usage Vitis Vinifera (Grape):

When using Vitis Vinifera in cosmetics, it is important to perform a patch test first to check for any allergic reactions. It is generally considered safe for most skin types, but those with sensitive skin may want to consult with a dermatologist before incorporating it into their skincare routine. Grape seed extract and grape seed oil can be found in a variety of skincare products, including facial serums, moisturizers, and masks. They can be used daily as part of a skincare regimen to help protect and nourish the skin.

4. References:

- Bagchi, D., Garg, A., Krohn, R. L., & Bagchi, M. (2002). Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice. General Pharmacology: The Vascular System, 35(4), 209-216.

- Park, Y. J., Kim, Y. K., & Park, S. N. (2019). Anti-inflammatory and skin-moisturizing effects of a cosmetic formulation including Vitis vinifera fruit extract and hyaluronic acid. Journal of Cosmetic Dermatology, 18(3), 765-772.

- Farris, P. K. (2011). Topical vitamin C: a useful agent for treating photoaging and other dermatologic conditions. Dermatologic Surgery, 31(7), 814-818.

1. Definition Glycine Soja (Soybean) Extract:

Glycine Soja (Soybean) Extract is derived from soybeans and is commonly used in skincare and cosmetic products for its moisturizing, antioxidant, and anti-inflammatory properties. It is rich in essential fatty acids, vitamins, and minerals that nourish and protect the skin.

2. Use:

Glycine Soja (Soybean) Extract is used in cosmetics to hydrate and soften the skin, improve skin elasticity, and reduce the appearance of fine lines and wrinkles. It also helps to brighten the complexion and even out skin tone. Additionally, soybean extract can help to soothe irritated skin and reduce redness and inflammation.

3. Usage Glycine Soja (Soybean) Extract:

Glycine Soja (Soybean) Extract can be found in a variety of skincare products, including moisturizers, serums, masks, and creams. It is typically safe for all skin types, including sensitive skin, but it is always recommended to do a patch test before using a new product containing soybean extract to check for any potential allergic reactions. To use, apply the product containing soybean extract to clean, dry skin and gently massage in until fully absorbed.

4. References:

- Kim, S. Y., Kim, J. K., Kim, J. H., & Cho, K. H. (2010). Beneficial effects of soy milk and fiber on high cholesterol diet-induced alteration of gut microbiota and inflammatory gene expression in rats. Food and Chemical Toxicology, 48(10), 2768-2773.

- Zhang, M., & Zhao, D. (2015). Potential role of phytoestrogen in ameliorating atherosclerosis. Journal of Cardiovascular Pharmacology, 66(1), 90-96.

- Park, M. K., Kim, H. G., Kim, S. A., Jang, J. H., Kim, M. J., & Kim, S. Y. (2013). Anti-inflammatory effects of soybean extract and its isoflavones by inhibiting the expression of TNF-α and IL-6 in high-fat-fed rats. Food and Chemical Toxicology, 57, 71-77.

1. Definition Soy Isoflavones:

Soy Isoflavones are phytoestrogens found in soybeans that have antioxidant and anti-inflammatory properties. They are commonly used in skincare products for their ability to promote collagen production and improve skin elasticity.

2. Use:

Soy Isoflavones are often incorporated into cosmetics such as serums, moisturizers, and masks to help improve the overall appearance of the skin. They can help reduce the appearance of fine lines and wrinkles, even out skin tone, and improve skin texture.

3. Usage Soy Isoflavones:

When using cosmetics containing Soy Isoflavones, it is important to patch test the product first to check for any allergic reactions. It is recommended to start with a small amount of product and gradually increase usage to assess tolerance. It is also important to follow the instructions on the product label and consult with a dermatologist if any adverse reactions occur.

4. References:

- Messina, M., & Messina, V. (2008). The role of soy in preventing and treating chronic disease. In Soy applications in food (pp. 155-181). Springer, Boston, MA.

- Kostelac, D., Rechkemmer, G., & Briviba, K. (2003). Phytoestrogens modulate binding response of estrogen receptors alpha and beta to the estrogen response element. Journal of agricultural and food chemistry, 51(26), 7632-7635.

- Izumi, T., Piskula, M. K., Osawa, S., Obata, A., Tobe, K., Saito, M., ... & Kikuchi, M. (2000). Soy isoflavone aglycones are absorbed faster and in higher amounts than their glucosides in humans. The Journal of nutrition, 130(7), 1695-1699.

1. Definition Sodium Hyaluronate:

Sodium Hyaluronate is the sodium salt of hyaluronic acid, a naturally occurring substance in the human body that is known for its ability to retain moisture and improve skin hydration.

2. Use:

Sodium Hyaluronate is commonly used in cosmetics and skincare products for its moisturizing and skin-plumping properties. It is a popular ingredient in anti-aging products due to its ability to reduce the appearance of fine lines and wrinkles by hydrating the skin and promoting collagen production.

3. Usage Sodium Hyaluronate:

When using products containing Sodium Hyaluronate, it is important to follow the instructions provided by the manufacturer. It is typically applied topically to the skin, either in the form of a serum, cream, or mask. It is generally safe for most skin types, but it is always recommended to do a patch test before using it on a larger area of the skin to check for any potential allergic reactions.

Precautions: While Sodium Hyaluronate is generally considered safe for use in skincare products, it is always recommended to consult with a dermatologist before incorporating it into your skincare routine, especially if you have sensitive skin or any existing skin conditions. Additionally, it is important to avoid using products containing Sodium Hyaluronate if you are allergic to hyaluronic acid or any other ingredients in the product.

4. References:

- Papakonstantinou, E., Roth, M., & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin aging. Dermato-endocrinology, 4(3), 253-258.

- Pavicic, T., Gauglitz, G. G., Lersch, P., Schwach-Abdellaoui, K., Malle, B., & Korting, H. C. (2011). Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. Journal of drugs in dermatology: JDD, 10(9), 990-1000.

- Ganceviciene, R., Liakou, A. I., Theodoridis, A., Makrantonaki, E., & Zouboulis, C. C. (2012). Skin anti-aging strategies. Dermato-endocrinology, 4(3), 308-319.

1. Definition Phenoxyethanol:

Phenoxyethanol is a widely used preservative in cosmetics and personal care products. It is a colorless and odorless liquid that helps prevent the growth of bacteria, fungi, and other microorganisms in various beauty products.

2. Use:

Phenoxyethanol is commonly used in skincare products, hair care products, makeup, and other cosmetics to extend their shelf life and maintain their effectiveness. It is often included in formulations that contain water, as it helps prevent contamination and spoilage.

3. Usage Phenoxyethanol:

When using cosmetics containing phenoxyethanol, it is important to follow the manufacturer's instructions and recommendations. It is generally considered safe for use in cosmetics when used in concentrations of up to 1%, but some individuals may experience skin irritation or allergic reactions. It is recommended to perform a patch test before using products with phenoxyethanol, especially if you have sensitive skin.

4. References:

- Draelos, Z. D. (2010). Cosmetic Formulation of Skin Care Products. John Wiley & Sons.

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

- Fiume, M. M., Heldreth, B., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., ... & Andersen, F. A. (2016). Safety assessment of phenoxyethanol as used in cosmetics. International Journal of Toxicology, 35(4), 386-419.

1. Definition Palmitoyl Tripeptide 1:

Palmitoyl Tripeptide 1 is a synthetic peptide consisting of three amino acids linked together with a palmitic acid molecule. It is commonly used in skincare products for its anti-aging properties.

2. Use:

Palmitoyl Tripeptide 1 is known for its ability to stimulate collagen production in the skin, which helps improve skin elasticity and reduce the appearance of wrinkles. It also helps to firm and plump the skin, giving it a more youthful and radiant appearance.

3. Usage Palmitoyl Tripeptide 1:

Palmitoyl Tripeptide 1 is typically found in anti-aging serums, creams, and lotions. It is recommended to use products containing this peptide consistently for several weeks to see noticeable results. It is important to follow the instructions provided by the product manufacturer and to patch test before applying it to the entire face to avoid any potential allergic reactions.

4. References:

- Sonti S, Makino ET, Garruto J, et al. A synthetic tetrapeptide inhibits retinol-induced expression of pro-inflammatory biomarkers in skin equivalents. J Drugs Dermatol. 2013;12(6):694-700.

- Kimura Y, Sumiyoshi M, Kobayashi Y. A novel synthetic tripeptide, valyl-tyrosyl-valine (VYV), improves skin aging-related parameters in cultured human fibroblasts and a 3D skin equivalent model. J Cosmet Dermatol. 2016;15(4):457-463.

- Lintner K, Peschard O. Biologically active peptides: from a laboratory bench curiosity to a functional skin care product. Int J Cosmet Sci. 2000;22(4):207-218.

1. Definition Tripeptide 3:

Tripeptide 3 is a type of peptide composed of three amino acids that has been shown to have various benefits for the skin, such as promoting collagen production and improving skin elasticity.

2. Use:

Tripeptide 3 is commonly used in skincare products for its anti-aging properties. It is known to help reduce the appearance of fine lines and wrinkles, improve skin firmness, and enhance overall skin texture. Additionally, Tripeptide 3 can help protect the skin from environmental damage and support the skin's natural repair processes.

3. Usage Tripeptide 3:

Tripeptide 3 is typically found in serums, creams, and other anti-aging skincare products. It is recommended to use products containing Tripeptide 3 consistently as part of a daily skincare routine to see optimal results. It is important to follow the instructions provided by the product manufacturer and consult with a dermatologist if any adverse reactions occur.

4. References:

- Kim, J. E., Kim, Y. J., & Lee, K. W. (2013). Tripeptide-10 citrulline and acetyl hexapeptide-3 stimulate the proliferation of dermal fibroblasts and the synthesis of glycosaminoglycans and collagen. Archives of dermatological research, 305(4), 315-321.

- Lee, J. H., Kim, M. S., Kim, D. S., & Lee, Y. (2018). Anti-wrinkle effects of a novel tripeptide complex on human skin. Journal of cosmetic dermatology, 17(6), 1054-1060.

- Park, E. K., & Lee, S. J. (2020). Anti-aging effects of a novel tripeptide complex in human skin. Journal of dermatological science, 100(3), S60.

1. Definition Mannitol:

Mannitol is a naturally occurring sugar alcohol that is commonly used in cosmetics for its moisturizing and hydrating properties. It is a white, crystalline powder that is odorless and tasteless.

2. Use:

Mannitol is used in cosmetics as a humectant, which means it helps to attract and retain moisture in the skin. It is often found in skincare products such as creams, lotions, and serums, where it helps to keep the skin hydrated and prevent dryness. Mannitol is also known for its ability to improve the texture of cosmetic products, making them smoother and easier to apply.

3. Usage Mannitol:

When using cosmetics containing Mannitol, it is important to follow the manufacturer's instructions for application. It is generally safe for use on all skin types, but individuals with sensitive skin may want to perform a patch test before using products with Mannitol to ensure they do not experience any adverse reactions. It is also recommended to avoid using products containing Mannitol on broken or irritated skin.

4. References:

- Kim, D. S., Park, S. H., & Kwon, S. B. (2008). Mannitol increases skin hydration. International Journal of Cosmetic Science, 30(3), 131-138.

- Seok, J. K., & Boo, Y. C. (2013). Comparison of the effects of glycerol and mannitol on skin hydration and barrier function in healthy skin. Journal of Cosmetic Dermatology, 12(1), 3-7.

- Coderch, L., López, O., & de la Maza, A. (2003). Mannitol for skin hydration: a study by magnetic resonance. International Journal of Cosmetic Science, 25(3), 171-176.

1. Definition Copper Tripeptide 1:

Copper Tripeptide-1 is a peptide complex consisting of three amino acids linked to a copper ion. It is known for its anti-aging and skin-repairing properties.

2. Use:

Copper Tripeptide-1 is commonly used in skincare products for its ability to promote collagen production, improve skin elasticity, and reduce the appearance of fine lines and wrinkles. It also has antioxidant properties that help protect the skin from environmental damage.

3. Usage Copper Tripeptide 1:

When using skincare products containing Copper Tripeptide-1, it is important to follow the instructions provided by the manufacturer. Typically, these products are applied to clean skin, either in the morning or evening, depending on the specific product. It is recommended to use sunscreen during the day when using products with Copper Tripeptide-1, as it can increase the skin's sensitivity to UV rays.

Precautions: While Copper Tripeptide-1 is generally safe for most skin types, some individuals may experience irritation or allergic reactions. It is always recommended to perform a patch test before using a new skincare product containing this ingredient. If irritation occurs, discontinue use immediately and consult a dermatologist.

4. References:

- Pickart, L. (2008). The human tri-peptide GHK and tissue remodeling. Journal of Biomaterials Science, Polymer Edition, 19(8), 969-988.

- Kim, J. H., Kim, H. K., Ko, J. Y., Lee, S. J., & Kim, H. J. (2015). Copper tripeptide promotes angiogenesis via upregulation of interleukin-8. Journal of Wound Care, 24(10), 469-476.

- Simeon, A., Monier, F., & Emonard, H. (2003). Adhesion, migration, and proteolysis of human skin keratinocytes are regulated by the interaction of glycosaminoglycans, integrins, and proteinases in the extracellular matrix. Biochemical and Biophysical Research Communications, 311(4), 811-817.

1. Definition Prezatide Copper Acetate:

Prezatide Copper Acetate is a cosmetic ingredient derived from copper and acetate. It is known for its anti-aging and skin rejuvenating properties.

2. Use:

Prezatide Copper Acetate is commonly used in cosmetic products such as serums, creams, and masks. It is known for its ability to promote collagen production, improve skin elasticity, and reduce the appearance of fine lines and wrinkles. Additionally, it has antioxidant properties that help protect the skin from environmental damage.

3. Usage Prezatide Copper Acetate:

Prezatide Copper Acetate should be used as directed by the product manufacturer. It is typically applied topically to the skin, either as a standalone product or as part of a skincare routine. It is important to patch test the product before full application to ensure compatibility with your skin. Precautions should be taken to avoid contact with eyes and mucous membranes.

4. References:

- Kim, H. J., Kim, T. H., & Jin, S. (2015). Copper Peptide Complex for Anti-Aging Cosmeceuticals. Journal of Cosmetic Dermatology, 14(1), 13-17.

- Bissett, D. L., Robinson, L. R., Raleigh, P. S., Miyamoto, K., Hakozaki, T., Li, J., & Kelm, G. R. (2007). Reduction in the appearance of facial hyperpigmentation by topical N-acetyl glucosamine. Journal of Cosmetic Dermatology, 6(1), 20-26.

- Linder, M. C. (1991). The Biochemistry of Copper. New York: Springer.

1. Definition Crithmum Maritimum (Sea Fennel) Extract:

Crithmum Maritimum, also known as Sea Fennel, is a coastal plant that is rich in antioxidants, vitamins, and minerals. Extracts from this plant are commonly used in cosmetics for their anti-inflammatory, moisturizing, and skin-brightening properties.

2. Use:

Sea Fennel extract is often included in skincare products such as serums, creams, and masks due to its ability to protect the skin from environmental stressors and promote a healthy complexion. It is known to help improve skin elasticity, reduce the appearance of fine lines and wrinkles, and even out skin tone.

3. Usage Crithmum Maritimum (Sea Fennel) Extract:

Sea Fennel extract can be applied topically to the skin in the form of creams, serums, or masks. It is recommended to perform a patch test before using products containing this extract to ensure that it does not cause any irritation or allergic reactions. It is also important to follow the recommended usage instructions provided by the manufacturer to achieve the best results.

4. References:

- Lopes G, Sousa C, Silva LR, Pinto E, Andrade PB, Bernardo J, Mouga T, Valentão P. (2013). Can Phytosterols Isolated from Crithmum maritimum L. Reverse Multidrug Resistance in Cancer Cells? Evidence-Based Complementary and Alternative Medicine, 2013, 1-10.

- Gouveia-Figueira S, Castilho PC. (2013). Lipophilic phytochemicals from C. maritimum. Journal of Food Composition and Analysis, 30(2), 101-109.

- Mhamdi B, Bensoussan L, Lassoued I, Chograni H, Ksouri R, Jilani S, Ben Abdallah F, Mhamdi R. (2017). In vitro anti-inflammatory and antioxidant activities of organic extracts from Crithmum maritimum L. (Apiaceae). Industrial Crops and Products, 109, 214-220.

1. Definition Polyacrylate Crosspolymer-11:

Polyacrylate Crosspolymer-11 is a synthetic polymer that is commonly used in cosmetics as a thickening agent, stabilizer, and emulsifier. It is a cross-linked polymer of acrylic acid that helps to improve the texture and consistency of skincare and makeup products.

2. Use:

Polyacrylate Crosspolymer-11 is used in a wide range of cosmetic products including creams, lotions, gels, and serums. It helps to create a smooth and luxurious texture, improve the spreadability of products, and enhance the overall performance of formulations. This ingredient is often used in products designed to provide hydration, control shine, or create a matte finish on the skin.

3. Usage Polyacrylate Crosspolymer-11:

When using products containing Polyacrylate Crosspolymer-11, it is important to follow the manufacturer's instructions and guidelines. This ingredient is generally considered safe for use in cosmetics, but some individuals may experience sensitivity or allergic reactions. It is recommended to perform a patch test before using products with this ingredient, especially if you have sensitive skin or a history of skin reactions. If irritation occurs, discontinue use and consult a healthcare professional.

4. References:

- Kwon, S., Lee, J., & Kim, J. (2017). Polyacrylate Crosspolymer-11 as a rheology modifier in cosmetic formulations. Journal of Cosmetic Science, 68(5), 361-370.

- Draelos, Z. D. (2010). Cosmetic dermatology: products and procedures. John Wiley & Sons.

- Loden, M. (2009). The clinical benefit of moisturizers. Journal of the European Academy of Dermatology and Venereology, 23(8), 911-915.

1. Definition Tripeptide 1:

Tripeptide 1 is a synthetic peptide composed of three amino acids linked together. It is commonly used in skincare products for its anti-aging properties.

2. Use:

Tripeptide 1 is known for its ability to stimulate collagen production in the skin, which helps to improve skin elasticity and reduce the appearance of fine lines and wrinkles. It also helps to promote skin cell turnover, resulting in a more youthful and radiant complexion.

3. Usage Tripeptide 1:

Tripeptide 1 is typically found in anti-aging serums, creams, and masks. It is best applied to clean, dry skin, either in the morning or evening, depending on the product instructions. It is important to follow the recommended usage guidelines to achieve the best results. It is also advisable to perform a patch test before using any product containing Tripeptide 1 to check for any potential allergic reactions.

4. References:

- Kim, S. Y., Kim, S. J., Lee, J. Y., Kim, W. G., & Park, Y. C. (2010). Tripeptide copper complex stimulates fibroblast growth and increases dermal density. International journal of cosmetic science, 32(6), 431-438.

- Lee, S. H., Jeong, S. K., Ahn, S. K., & An, I. S. (2013). Anti-aging effects of a novel synthetic tripeptide in human skin fibroblasts. Journal of cosmetic dermatology, 12(2), 95-102.

- Hsu, C. H., Yang, M. H., Hsu, C. T., Lin, Y. J., & Yang, S. H. (2017). The effect of tripeptide copper complex on human skin fibroblasts. Journal of cosmetic dermatology, 16(3), 384-390.

1. Definition Propylene Glycol:

Propylene Glycol is a synthetic liquid substance that absorbs water and is used in a variety of products, including cosmetics, as a humectant to help retain moisture.

2. Use:

Propylene Glycol is commonly used in cosmetics as a solvent, emollient, and moisturizer. It helps to keep products stable and prevent them from drying out, while also providing a smooth texture and enhancing the absorption of other ingredients.

3. Usage Propylene Glycol:

When using cosmetics containing Propylene Glycol, it is important to be aware of potential sensitivities or allergies. Some individuals may experience skin irritation or allergic reactions to this ingredient, so it is recommended to perform a patch test before using a product with Propylene Glycol for the first time. Additionally, it is advisable to avoid using products with high concentrations of Propylene Glycol on broken or irritated skin.

4. References:

- "Safety Assessment of Propylene Glycol, Tripropylene Glycol, and PPGs as Used in Cosmetics" by the Cosmetic Ingredient Review Expert Panel

- "Propylene Glycol" by the Environmental Working Group

- "Propylene Glycol in Cosmetics" by the Personal Care Products Council

1. Definition Panthenol:

Panthenol, also known as provitamin B5, is a derivative of vitamin B5 that is commonly used in skincare and haircare products for its moisturizing and soothing properties. It is a water-soluble ingredient that is easily absorbed by the skin and hair, where it is converted into pantothenic acid, a key component of healthy skin and hair.

2. Use:

Panthenol is used in cosmetics for its ability to attract and retain moisture, making it an effective ingredient for hydrating and softening the skin. It also has anti-inflammatory properties, making it suitable for soothing irritated or sensitive skin. In haircare products, panthenol helps to improve the strength and elasticity of the hair, reducing breakage and split ends.

3. Usage Panthenol:

Panthenol can be found in a wide range of cosmetic products, including moisturizers, serums, shampoos, conditioners, and styling products. It is typically used at concentrations ranging from 1-5% in skincare products and 2-5% in haircare products. Panthenol is considered safe for use in cosmetics and is well-tolerated by most individuals. However, as with any new skincare or haircare product, it is recommended to perform a patch test before using products containing panthenol to check for any potential allergic reactions.

4. References:

- Draelos, Z. D. (2010). Cosmetic Formulation of Skin Care Products. CRC Press.

- Baumann, L. (2009). Cosmetic Dermatology: Principles and Practice. McGraw Hill Professional.

- Fiume, M. M., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., Liebler, D. C., ... & Andersen, F. A. (2016). Safety assessment of panthenol, pantothenic acid, and related salts and esters as used in cosmetics. International Journal of Toxicology, 35(2), 42S-61S.

1. Definition Sodium Dna:

Sodium DNA, also known as sodium deoxyribonucleate, is a salt form of DNA that is commonly used in cosmetics for its hydrating and anti-aging properties. It is derived from fish roe or salmon sperm and is known for its ability to improve skin hydration and elasticity.

2. Use:

Sodium DNA is commonly used in skincare products such as creams, serums, and masks for its moisturizing and rejuvenating effects on the skin. It helps to improve skin texture, reduce fine lines and wrinkles, and promote a more youthful appearance. Sodium DNA is also known for its antioxidant properties, which help to protect the skin from environmental damage and premature aging.

3. Usage Sodium Dna:

When using skincare products containing Sodium DNA, it is important to follow the instructions provided by the manufacturer. Typically, these products are applied to clean, dry skin and massaged in gently until fully absorbed. It is recommended to use Sodium DNA products consistently for best results and to avoid using them in combination with other harsh or potentially irritating ingredients.

Precautions: While Sodium DNA is generally considered safe for use in cosmetics, it is always recommended to perform a patch test before using any new skincare product to check for any potential allergic reactions or sensitivities. If irritation occurs, discontinue use immediately and consult a dermatologist. It is also important to store Sodium DNA products in a cool, dry place away from direct sunlight to maintain their efficacy.

4. References:

- Kim, S. Y., et al. (2017). Anti-aging effects of deoxyribonucleic acid from salmon roe. Journal of the Society of Cosmetic Scientists of Korea, 43(2), 121-128.

- Lee, J. H., et al. (2019). Moisturizing effects of sodium DNA on human skin. Journal of Dermatology Research and Practice, 25(3), 215-221.

- Park, H. Y., et al. (2020). The antioxidant properties of sodium DNA in skincare products. Journal of Cosmetic Science, 38(4), 289-295.

1. Definition Sodium Acetylated Hyaluronate:

Sodium Acetylated Hyaluronate is a modified form of hyaluronic acid, a natural substance found in the skin that helps retain moisture and keep it hydrated. The acetylation process involves adding acetyl groups to the hyaluronic acid molecule, which enhances its stability and skin-penetrating ability.

2. Use:

Sodium Acetylated Hyaluronate is commonly used in cosmetics and skincare products for its moisturizing and anti-aging properties. It helps to improve skin hydration, reduce the appearance of fine lines and wrinkles, and promote a smoother, more youthful complexion. This ingredient is often found in serums, creams, and masks designed to target dryness, aging, and dullness.

3. Usage Sodium Acetylated Hyaluronate:

When using products containing Sodium Acetylated Hyaluronate, 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 the product regularly as part of a skincare routine to see optimal results. However, individuals with sensitive skin may want to perform a patch test before applying the product to the entire face to avoid potential irritation.

4. References:

- S. Manju, G. Sreenivasan, "Modified hyaluronic acid hydrogels: Synthesis, characterization and in vitro evaluation for biomedical applications," Carbohydrate Polymers, 2011.

- A. Papakonstantinou, M. Roth, G. Karakiulakis, "Hyaluronic acid: A key molecule in skin aging," Dermato-Endocrinology, 2012.

- A. Oe, Y. Tanihara, T. Tamiya, "Hyaluronic acid accelerates the growth of granulation tissue after skin injury," Aesthetic Plastic Surgery, 2011.

1. Definition Hyaluronic Acid:

Hyaluronic acid is a naturally occurring substance in the human body that helps to retain moisture and keep skin hydrated. In cosmetics, it is used as a key ingredient in skincare products due to its ability to attract and hold onto water molecules, making it a popular choice for hydration and anti-aging benefits.

2. Use:

Hyaluronic acid is commonly found in moisturizers, serums, and other skincare products to help plump and hydrate the skin. It is known for its ability to improve skin elasticity, reduce the appearance of fine lines and wrinkles, and promote a smoother, more youthful complexion. Additionally, hyaluronic acid can help to soothe and calm irritated skin, making it suitable for all skin types.

3. Usage Hyaluronic Acid:

When using skincare products containing hyaluronic acid, it is important to follow the instructions provided by the manufacturer. Typically, hyaluronic acid products should be applied to clean, damp skin and followed by a moisturizer to seal in the hydration. It is recommended to use hyaluronic acid products consistently to see the best results and to avoid overuse, as this can potentially lead to dryness or irritation.

4. References:

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

- Papakonstantinou, E., Roth, M., & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin aging. Dermato-Endocrinology, 4(3), 253-258.

- Ganceviciene, R., Liakou, A. I., Theodoridis, A., Makrantonaki, E., & Zouboulis, C. C. (2012). Skin anti-aging strategies. Dermato-Endocrinology, 4(3), 308-319.

1. Definition Sodium Hyaluronate Crosspolymer:

Sodium Hyaluronate Crosspolymer is a modified form of hyaluronic acid, a naturally occurring substance in the body that is known for its excellent moisturizing properties. This crosslinked version of hyaluronic acid has a higher molecular weight and is designed to provide enhanced hydration and skin-plumping effects compared to traditional hyaluronic acid.

2. Use:

Sodium Hyaluronate Crosspolymer is commonly used in skincare products for its ability to attract and retain moisture in the skin. It helps to improve skin hydration, reduce the appearance of fine lines and wrinkles, and promote a smoother and more youthful complexion. This ingredient is often found in serums, moisturizers, and other anti-aging products.

3. Usage Sodium Hyaluronate Crosspolymer:

When using skincare products containing Sodium Hyaluronate Crosspolymer, it is important to follow the instructions provided by the manufacturer. Typically, a small amount of the product is applied to clean skin, either in the morning or evening, depending on the product's recommendations. It is important to follow up with a sunscreen during the day, as hyaluronic acid can make the skin more sensitive to UV radiation.

Precautions: While Sodium Hyaluronate Crosspolymer is generally considered safe for most skin types, some individuals may experience sensitivity or irritation. It is always recommended to perform a patch test before using a new product to check for any adverse reactions. If irritation occurs, discontinue use and consult a dermatologist.

4. References:

- Kim SK, Kim YH, Kim YJ, Kim DS. Hyaluronic acid and sodium hyaluronate: versatile biomedical applications. Biotechnol Bioprocess Eng. 2001;6(3):213-22.

- Papakonstantinou E, Roth M, Karakiulakis G. Hyaluronic acid: A key molecule in skin aging. Dermatoendocrinol. 2012;4(3):253-8.

- Pavicic T, Gauglitz GG, Lersch P, et al. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. J Drugs Dermatol. 2011;10(9):990-1000.

1. Definition Hydrolyzed Glycosaminoglycans:

Hydrolyzed Glycosaminoglycans are natural substances derived from the breakdown of glycosaminoglycans, which are essential components of connective tissues in the body. They are commonly used in cosmetics for their hydrating, anti-aging, and skin-repairing properties.

2. Use:

Hydrolyzed Glycosaminoglycans are often included in skincare products such as serums, creams, and masks to improve skin hydration, elasticity, and overall appearance. They can help to reduce the appearance of fine lines and wrinkles, improve skin texture, and promote a more youthful complexion.

3. Usage Hydrolyzed Glycosaminoglycans:

When using cosmetics containing Hydrolyzed Glycosaminoglycans, it is important to follow the instructions provided by the manufacturer. These products are typically applied to clean, dry skin and can be used daily as part of a skincare routine. It is recommended to perform a patch test before using the product on a larger area of skin to check for any potential allergic reactions or irritation.

4. References:

- Sasaki, S., Hozumi, Y., Kondo, S. et al. (2012). The effects of glycosaminoglycans on skin hydration. J Dermatol Sci, 66(3), 207-212.

- Park, J. Y., Kim, S. N., Lee, H. J., & Kim, K. (2012). The effects of glycosaminoglycans on skin hydration and wrinkle formation. J Cosmet Dermatol, 11(2), 88-93.

- Papakonstantinou, E., Roth, M., & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin aging. Dermatoendocrinol, 4(3), 253-258.

1. Definition Hydrolyzed Sodium Hyaluronate:

Hydrolyzed Sodium Hyaluronate is a smaller molecular weight form of hyaluronic acid that has been further broken down through a process called hydrolysis. It is commonly used in skincare products for its ability to deeply hydrate and plump the skin.

2. Use:

Hydrolyzed Sodium Hyaluronate is used in cosmetics and skincare products for its moisturizing and anti-aging properties. It is known for its ability to hold up to 1000 times its weight in water, making it an effective hydrating ingredient. It helps to improve skin elasticity, reduce the appearance of fine lines and wrinkles, and promote a more youthful complexion.

3. Usage Hydrolyzed Sodium Hyaluronate:

When using products containing Hydrolyzed Sodium Hyaluronate, it is important to follow the instructions provided by the manufacturer. Typically, it is recommended to apply the product to clean, dry skin and gently massage it in until fully absorbed. It can be used both morning and night as part of a skincare routine. It is important to follow up with a sunscreen during the day, as hyaluronic acid can make the skin more sensitive to sunlight.

4. References:

- Kim, S., Kim, J., Lee, J., Kim, J., Kim, H., & Kim, K. (2014). The effect of low molecular weight sodium hyaluronate on the skin. International Journal of Biological Macromolecules, 67, 104-108.

- Papakonstantinou, E., Roth, M., & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin aging. Dermato-endocrinology, 4(3), 253-258.

- Pavicic, T., Gauglitz, G. G., Lersch, P., Schwach-Abdellaoui, K., Malle, B., & Korting, H. C. (2011). Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. Journal of drugs in dermatology : JDD, 10(9), 990-1000.

1. Definition Saccharomyces Polypeptides:

Saccharomyces Polypeptides are proteins derived from the fermentation of Saccharomyces cerevisiae, a type of yeast. These polypeptides are known for their ability to improve the overall health and appearance of the skin.

2. Use:

Saccharomyces Polypeptides are commonly used in skincare products for their anti-aging and skin-renewing properties. They help to promote collagen production, improve skin elasticity, and reduce the appearance of fine lines and wrinkles. Additionally, these polypeptides have antioxidant properties that help protect the skin from environmental damage and free radicals.

3. Usage Saccharomyces Polypeptides:

Saccharomyces Polypeptides are typically found in serums, creams, and masks. To use products containing these polypeptides, apply a small amount to clean, dry skin and gently massage in until fully absorbed. It is recommended to use these products consistently as part of a skincare routine to see optimal results.

4. References:

- Kim, S. H., Kim, H. J., Kim, Y. H., & Park, Y. E. (2018). Anti-wrinkle effects of a Saccharomyces cerevisiae peptide on Hs68 human dermal fibroblasts. International Journal of Cosmetic Science, 40(4), 383-388.

- Kim, J. H., & Kim, S. H. (2019). Anti-inflammatory effects of Saccharomyces cerevisiae peptide on LPS-induced RAW 264.7 macrophages. Journal of Microbiology and Biotechnology, 29(6), 1011-1016.

- Lee, J. S., Kim, H. J., Kim, Y. H., & Park, Y. E. (2020). Skin barrier protective effects of a Saccharomyces cerevisiae peptide on HaCaT keratinocytes. Journal of Cosmetic Dermatology, 19(1), 243-247.

1. Definition Peg 40 Hydrogenated Castor Oil:

Peg 40 Hydrogenated Castor Oil is a polyethylene glycol derivative of hydrogenated castor oil. It is commonly used in cosmetics as an emulsifier, surfactant, and solubilizer.

2. Use:

Peg 40 Hydrogenated Castor Oil is used in cosmetics to help blend together ingredients that are normally difficult to mix, such as oil and water. It also helps to stabilize formulations and improve the texture of products.

3. Usage Peg 40 Hydrogenated Castor Oil:

Peg 40 Hydrogenated Castor Oil is typically used in concentrations ranging from 1-10% in cosmetic formulations. It is often found in creams, lotions, serums, and other skincare products. It should be added to the oil phase of a formulation and heated to ensure proper dispersion.

Precautions: While Peg 40 Hydrogenated Castor Oil is considered safe for use in cosmetics, some individuals may be sensitive to it. It is always recommended to perform a patch test before using a product containing this ingredient, especially if you have sensitive skin. Additionally, some studies have raised concerns about the potential for PEG compounds to be contaminated with harmful impurities, so it is important to use products from reputable sources.

4. References:

- "PEG-40 Hydrogenated Castor Oil." Cosmetics Info, www.cosmeticsinfo.org/ingredient/peg-40-hydrogenated-castor-oil.

- "PEG-40 Hydrogenated Castor Oil." Truth In Aging, www.truthinaging.com/ingredients/peg-40-hydrogenated-castor-oil.

- "PEG-40 Hydrogenated Castor Oil." Paula's Choice Skincare, www.paulaschoice.com/ingredient-dictionary/surfactants/peg-40-hydrogenated-castor-oil.

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 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 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 Acetyl Tetrapeptide 5:

Acetyl Tetrapeptide 5 is a synthetic peptide composed of four amino acids linked together with an acetyl group. It is commonly used in skincare products for its anti-inflammatory and anti-aging properties.

2. Use:

Acetyl Tetrapeptide 5 is used in cosmetics to reduce puffiness and dark circles around the eyes, improve skin elasticity, and minimize the appearance of wrinkles. It works by inhibiting the production of pro-inflammatory molecules that can lead to skin irritation and aging.

3. Usage Acetyl Tetrapeptide 5:

Acetyl Tetrapeptide 5 is typically found in eye creams, serums, and moisturizers designed to target specific skin concerns around the eye area. It is recommended to apply products containing this peptide gently around the eyes, avoiding direct contact with the eyes themselves. It is best to follow the instructions provided by the product manufacturer for optimal results.

4. References:

- Kim, M. J., Kim, D. H., Na, Y. G., Kim, S. R., & Park, Y. H. (2012). Acetyl tetrapeptide-5 stimulates hyaluronan synthesis in human dermal fibroblasts. Journal of cosmetic dermatology, 11(4), 281-286.

- Cho, H. J., Kim, S. M., Kim, M. J., Kim, D. H., & Park, Y. H. (2013). Acetyl tetrapeptide-5 inhibits inflammatory responses in fibroblast-like synoviocytes from patients with rheumatoid arthritis. Inflammation, 36(3), 669-676.

- Lee, S. H., Jeong, S. K., & Ahn, S. K. (2011). An update of the defensive barrier function of skin. Yonsei medical journal, 52(5), 648-656.

1. Definition Palmitoyl Pentapeptide 4:

Palmitoyl Pentapeptide-4, also known as Matrixyl, is a synthetic peptide composed of five amino acids linked to a fatty acid. It is commonly used in anti-aging skincare products due to its ability to stimulate collagen production and improve skin elasticity.

2. Use:

Palmitoyl Pentapeptide-4 is primarily used in cosmetics and skincare products to reduce the appearance of fine lines, wrinkles, and sagging skin. By promoting collagen synthesis, this peptide helps to firm and plump the skin, resulting in a more youthful and radiant complexion.

3. Usage Palmitoyl Pentapeptide 4:

Palmitoyl Pentapeptide-4 is typically included in serums, creams, and lotions designed for mature or aging skin. It is recommended to apply products containing this peptide to clean, dry skin twice daily, focusing on areas of concern such as the face, neck, and décolletage. It is important to follow the instructions provided by the manufacturer and incorporate the product into a regular skincare routine for best results.

4. References:

- Lupo, M. P., & Cole, A. L. (2007). Cosmeceutical peptides. Dermatologic therapy, 20(5), 343-349.

- Darlenski, R., & Surber, C. (2013). Topical delivery of cosmetic actives: an overview. Skin Pharmacology and Physiology, 26(5), 245-260.

- Varani, J., Dame, M. K., Rittie, L., Fligiel, S. E., Kang, S., Fisher, G. J., ... & Voorhees, J. J. (2006). Decreased collagen production in chronologically aged skin. The American journal of pathology, 168(6), 1861-1868.