Thelactic acid is part of the alpha-hydroxy acids (A.H.A.) family. Naturally present in the skin, it is produced by the beneficial bacteria of the skin flora. Thus, it is referred to as apost-biotic. Furthermore, this substance can also be found in certain foods such as sugar cane and wine.
Many cosmetic products are formulated with lactic acid, including serums, tonics, and creams. This active ingredient is highly valued primarily for its keratolytic properties. Indeed, lactic acid eliminates dead cells on the surface of the epidermis, accelerating cell renewal. Thanks to its properties, lactic acid is an excellent active ingredient to combat signs of ageing (wrinkles, fine lines) and imperfections (acne, blackheads, post-acne spots). In addition to its exfoliating power, lactic acid maintains good hydration of the horny layer due to its hygroscopic properties. Furthermore, scientific studies have also highlighted the depigmenting properties of lactic acid. Indeed, lactic acid inhibits the activity of enzymes involved in the process of melanogenesis (the mechanism responsible for the production of melanin): the tyrosinases.
Compared to other molecules in the A.H.A. family, particularly glycolic acid, thelactic acid has a gentle exfoliating power. Unlike glycolic acid, which penetrates deeply into the epidermis and can cause irritation, thelactic acid acts on the surface. This is due to its higher molecular weight, which prevents it from crossing the epidermis. Furthermore, as lactic acid is a molecule naturally present on the skin, at the level of the Natural Moisturising Factor (NMF), it is better tolerated by the skin.
Thus, lactic acid is a gentle exfoliant suitable for all skin types, even the most sensitive. It helps to accelerate cell renewal while maintaining good hydration of the epidermis.