Lactic acid

Lactic acid is a plant-derived acid produced by fermentation. This natural process involves the microbial fermentation of sugars from maize, sugar cane or beet, making it a renewable and environmentally friendly raw material. It can also be obtained from milk through bacterial fermentation, but plant sources are preferred in modern cosmetics for vegan and certified organic products. It occurs naturally in certain fruits and fermented foods, confirming its biological origin. Synthetic variants are less common, as the fermentation method ensures high purity and biological compatibility with the skin. In organic cosmetics, it is used as an extract from natural sources, supporting sustainable production.

It is an AHA (alpha hydroxy acid) that smooths and rejuvenates the skin, supports cell renewal and improves skin elasticity. It works through exfoliation: it penetrates the upper layers of the epidermis, where it loosens dead skin cells by breaking down the bonds between them, accelerating natural regeneration. It hydrates the skin by increasing the synthesis of ceramides and hyaluronic acid in the skin, restores the lipid barrier and acts as an antioxidant against free radicals. It soothes irritation and reduces inflammation. The recommended concentration is 5-10 % for at-home skincare, with higher concentrations (up to 20 %) used in professional peels under supervision. It is a gentler alternative to glycolic acid in cosmetics. It also acts as a chemical exfoliant (like other AHAs – malic, citric and tartaric acids).

It is particularly suitable for ageing and mature skin. It is recommended for dry, dehydrated, sensitive, oily and acne-prone skin. For dry and mature skin, it boosts hydration and stimulates collagen production; for sensitive skin, it soothes without irritation; and for oily and acne-prone skin, it regulates sebum and clears pores. Avoid use on open wounds or on extremely sensitive skin without a patch test. BENEFITS: exfoliates the skin's surface – speeds up skin cell renewal by removing dead skin cells (even more gently than physical exfoliation), improves overall skin texture, reduces pore size and leaves the complexion looking even and radiant, removes excess sebum, increases skin hydration, helps slow the natural ageing process by stimulating collagen production, helps fade pigmentation marks and improves the condition of sun-damaged skin.

Clinical studies confirm its effectiveness: lactic acid at a concentration of 12 %, used 3x a week for 12 weeks, improved skin hydration by 81 % and reduced fine lines in women with photoaged skin (Journal of Cosmetic Dermatology, 2008). Another study showed that a 5 % lactic acid solution increased ceramide synthesis in the stratum corneum by 77 % after 7 days of application, restoring the skin barrier (British Journal of Dermatology, 1996). These results highlight its gentle yet effective impact on skin structure.