The Benefits of Lactic Acid for Skin.

Lactic acid is an organic acid. It belongs to the family of alpha-hydroxy acids (AHA). It was first extracted from milk by a Swedish chemist, Carl Wilhelm Scheele. However, lactic acid is not only found in milk. It is present in food (certain fruits and vegetables), in wine but also in the human body (during a very intense muscular effort, lactic acid is produced).

Moreover, lactic acid is found naturally in the skin, in the NMF (Natural Moisturizing Factor) which improves the skin's hydration.

Note: The NMF represents 30% of the total dry weight of the stratum corneum. It is composed of amino acids, their derivatives as well as extracellular compounds such as lactic acid or urea. Its hygroscopic properties enable it to capture and retain water in the stratum corneum, thus maintaining good skin hydration.

In cosmetics, lactic acid for skin care purposes is an active ingredient that is widely used for its many benefits. However, it remains a powerful active ingredient that can cause some side effects such as sun sensitivity and irritation.  For this reason, it is authorized at a maximum concentration of 10% in cosmetic products according to the European regulation.

As previously mentioned, lactic acid products are highly appreciated because of the many benefits for skin and complexion.

• Keratolytic properties: Lactic acid is a chemical exfoliant, i.e., it eliminates dead cells on the skin's surface. It dissolves the intercellular links thus stimulating the cellular renewal. It revives dull complexions and prevents the appearance of imperfections (pimples, blackheads). A study has proven that lactic acid at a concentration of 2% is more effective than salicylic acid at a concentration of 2% in reducing inflammatory pimples and blackheads. Unlike glycolic acid, which is also part of the AHA family, lactic acid is a gentle exfoliant. It is suitable for all skin types, even the most sensitive. This is due to its higher molecular weight. It therefore penetrates less deeply through the epidermis and acts superficially.

  Note: In vivo studies have proven that the application of 12% lactic acid for 3 months is responsible for a reduction in wrinkles, an improvement in skin elasticity and an increase in dermal cells.

• Moisturizing properties: In addition to exfoliating the skin, lactic acid moisturizes the skin. This is due to its hygroscopic properties. Indeed, lactic acid is part of the NMF (Natural Moisturizing Factor) which improves skin hydration.

• Depigmenting properties: Lactic acid inhibits the activity of enzymes involved in the melanogenesis process (mechanism at the origin of melanin production): tyrosinase. The results of the studies prove that the topical application of lactic acid considerably reduces hyperpigmentation. However, these studies were carried out using a peel with 82% lactic acid (this is far above the authorized concentration in cosmetics, which is 10%). The use of lactic acid in high doses requires the intervention of a health professional.