What you need to know about lactic acid.

Lactic acid is a chemical exfoliant that originates from the fermentation of lactose, a carbohydrate found in milk. Naturally present in the skin, it is produced by the beneficial bacteria of the skin flora. It is thus classified as a post-biotic. In addition, this substance is also found in certain foods such as sugar cane and wine. It imparts a sour taste characteristic of fermented foods.

In cosmetics, its use dates back to ancient Egypt. To achieve soft skin, Cleopatra loved to take baths in donkey milk, which therefore contained a large amount oflactic acid. This A.H.A. helps to remove dead cells from the epidermis to make the skin of the face smoother, more radiant and uniform. As a reminder, A.H.A.s are water-soluble organic compounds recommended for rejuvenating the skin by stimulating cell renewal.

In skincare, lactic acid can be of synthetic or plant origin. At Typology, the lactic acid present in the gentle peeling serum is obtained by fermenting the sugar found in corn seeds using specific bacteria, such as Lactobacillus.

When applied topically, lactic acid offers numerous benefits:

• It contributes to the removal of dead cells that clog the pores and smooths the skin texture. It dissolves intercellular bonds, thus stimulating cellular renewal. This process is called exfoliation. Therefore, it revives dull complexions and prevents the appearance of blackheads.

• It effectively hydrates the epidermis. Indeed, researchers have demonstrated that lactic acid enhances the skin's natural hydration factor.
  

• It helps to fade pigmented spots and smooth fine lines.

• It lightens scars and post-inflammatory redness, particularly acne marks.
  

Furthermore, lactic acid is used in cosmetic formulas as a pH regulator, which needs to be slightly acidic to properly adapt to the epidermis.

This fruit acid is primarily used in the treatment of dandruff. Indeed, it reduces potential itching and regulates the occurrence of oily dandruff. It helps to prevent the blockage of hair follicles and to maintain a healthy scalp.

Lactic acid, due to its moisturising properties, also helps to prevent the drying out of hair fibres and thus the occurrence of split ends.

Lactic acid is gentle compared to other AHAs. Generally, it is recommended for individuals with sensitive skin who are looking to achieve a gentle exfoliation. This molecule, being larger in size than glycolic acid, will penetrate less deeply into the epidermis and will therefore be less irritating than the latter. Lactic acid is therefore an excellent alternative for skin that has not tolerated products containing glycolic acid.

However, it remains a potent active ingredient that can cause some side effects such as sun sensitivity and irritation. The latter can manifest as itching, burning sensations, redness... For this reason, as an exfoliant, lactic acid is permitted at a maximum concentration of 10% in a cosmetic product according to European cosmetic regulations.

Lactic acid is a substance that increases photosensitivity. Therefore, it is preferably applied in the evening, to avoid causing skin irritations when exposed to sunlight. We still advise you to use a broad-spectrum sunscreen the following day and subsequent days.

Before using any lactic acid skincare product, perform a skin tolerance test. Apply a few drops of your product to the inside of your arm or the back of your hand and wait 24 hours. If you notice any skin reaction, do not use your lactic acid product on your face.

Please note : Skincare treatments with lactic acid are not recommended if you are undergoing a treatment based on retinoids.

We have formulated a serum containing 10% lactic acid. Highly concentrated, it provides your skin with gentle exfoliation due to its superficial action. By ridding the skin of its dead cells, our gentle peeling serum revives the complexion's radiance and fights against imperfections. The skin is smooth and glowing. Additionally, it contains an antioxidant, theacerola extract, which combats the free radicals responsible for a dull complexion. Our serum is suitable for all skin types (oily, dry, and combination skin). It is also suitable for sensitive skin as, unlike glycolic acid, it is non-irritating and penetrates less deeply.

You can also find lactic acid in our peeling mask. Enriched with A.H.A. and P.H.A, it exfoliates the skin, leaving it smooth and soft. This concentrated gel mask eliminates dead cells to unclog pores and refine skin texture. Over time, it also helps to reduce the presence of blackheads. Its use is not recommended for people with sensitive skin, due to its high concentration of A.H.A.

• SMITH W. P. Epidermal and dermal effects of topical lactic acid. Journal of the American Academy of Dermatology (1996).

• SACHDEVA S. Lactic acid peeling in superficial acne scarring in Indian skin. Journal of Cosmetic Dermatology (2010).

• RATHI S.K. Treatment of Acne Vulgaris: The Current Landscape. Indian Journal of Dermatology (2011).