Collagen: How to Use It?

Collagen is a fibrous protein found in various body structures such as the skin, cartilage, ligaments, and hair. It is also present in numerous cosmetic products, primarily aimed at the skin, although there are some hair products containing collagen. Typically incorporated at a concentration of 1 to 2% in these products, this molecule helps to enhance the skin's hydration levels by forming a film on its surface. Additionally, collagen attracts and retains water molecules, thereby protecting the epidermis from dehydration.

In addition to its hydrating properties, collagen also exhibits antioxidant effects, making it a popular ingredient in skincare formulations aimed at preventing wrinkles. Demonstrated with collagen hydrolysate, these effects are particularly significant due to the low molecular weight of the peptides. Penetrating the skin more easily than the native molecule, collagen peptides can also activate fibroblasts, thereby stimulating the production of collagen, elastin, and glycosaminoglycans. This results in improved suppleness, elasticity, and hydration of the skin.

Key Takeaway : Collagen is a popular cosmetic ingredient, commonly found in creams, serums, or masks aimed at mature skin or targeting skin aging.

In recent years, collagen has also made its way into the realm of nutricosmetics. Drinkable collagen, collagen powder to dilute, collagen capsules... It comes in many forms, all promising similar benefits: a more radiant complexion, more supple skin, and strengthened hair and nails . However, one might question the actual effects of these collagen treatments. Indeed, once the protein is ingested, it is broken down into amino acids in order to cross the intestinal barrier. These amino acids can then be used by the body to reconstitute proteins, but it is not guaranteed that they will specifically form collagen. The same applies to collagen peptides, which are also hydrolysed into amino acids.

Despite these uncertainties, numerous studies have focused on the effects of collagen on the skin and hair, yielding positive results in terms of skin hydration and elasticity, the appearance of wrinkles, and the health of hair and nails. Regarding the recommended dose of collagen, it varies between 2 and 15 g per day. According to studies, the effects of collagen treatments can appear after two weeks. The duration and frequency of these treatments are relatively variable. Suppliers generally recommend a collagen treatment of three to six months once a year or two to three one-month collagen treatments once a year.

Even though oral intake of collagen is often well tolerated, it is recommended to seek medical advice before starting a course, especially if you have food allergies.

• RODRIGUEZ M.I. Collagen: A review on its sources and potential cosmetic applications. Journal of Cosmetic Dermatology (2018).

• AHUIRRE-ÁLVAREZ G. & al. Collagen hydrolysates for skin protection: oral administration and topical formulation. Antioxidants (2020).

• CHEN C. & al. Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients (2023).