What are the benefits of lactic acid?

The lactic acid is an organic acid. It belongs to the family of alpha-hydroxy acids (A.H.A.). 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, and also in the human body (during very intense muscular effort, lactic acid is produced).

Furthermore, lactic acid is naturally found in the skin, in the NMF which enhances skin hydration.

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

In cosmetics, lactic acid is a widely used active ingredient due to its numerous benefits. However, it remains a potent active ingredient that can cause some side effects such as sun sensitivity and irritation. For this reason, it is permitted at a maximum concentration of 10% in cosmetic products according to European regulations.

As previously mentioned, lactic acid is a highly valued active ingredient due to its numerous benefits for the skin.

• Keratolytic Properties : Lactic acid is a chemical exfoliant, meaning it removes dead cells from the skin's surface. It dissolves intercellular bonds, thus stimulating cell renewal. It revives dull complexions and prevents the appearance of blemishes (pimples, blackheads). A study has indeed proven a better efficacy of lactic acid at a concentration of 2% compared to salicylic acid at a concentration of 2% as well for reducing inflammatory pimples and blackheads. Unlike glycolic acid, which is also part of the A.H.A. family, lactic acid is a gentle exfoliant. It is suitable for all skin types, even the most sensitive. This is explained by its higher molecular weight. Therefore, it penetrates less deeply through the epidermis and acts superficially.

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

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

• Depigmenting Properties : Lactic acid works to inhibit the activity of enzymes involved in the process of melanogenesis (the mechanism responsible for melanin production): the tyrosinases. The results of studies prove that the topical application of lactic acid significantly reduces pigmented spots. However, these studies were conducted using a peel with 82% lactic acid (this is well above the concentration allowed in cosmetics, which is 10%). The use of high-dose lactic acid requires the intervention of a healthcare professional.