What is Lactic Acid?

Zara Kassam BSc (Hons), MRes, PhD researcher


What is Lactic acid?

Lactic acid is one of the most popular Alpha hydroxy acids (AHAs) in skin care today. AHAs are acids derived from foods and, as it turns out a type of acid that’s safe to apply to our skin. Lactic Acid is derived from milk products.


What does it do?

Lactic acid is marketed as a powerful ingredient in the skin care industry; it is applied topically and regularly to your skin help reduces the appearance of aging, and can be an especially good remedy against fine lines, wrinkles and other signs of premature aging from sun damage. This results in improved skin texture, by exfoliating the surface of the skin by breaking down dead skin cells, allowing natural shedding to occur.



Lactic acid is diluted for skin care to concentrations of between 5-12 %; these are considered safe for use. AHAs remove off the outer layer of skin, which makes them effective exfoliators, but in the process, they leave skin more vulnerable to the damaging effects of UV rays, a gentle lotion or cream may be applied following the use to help soothe the skin. A sunscreen with a sun-protection factor of 30 or higher is generally recommended.


Other names

2-Hydroxypropanoic acid[4]

[1] Dawson, R. M. C.; et al. (1959). Data for Biochemical Research. Oxford: Clarendon Press.

[2] Alpha Hydroxy Acids for Skin Care”. Cosmetic Dermatology, Supplement: 1–6. October 1994.

[3] Kempers, S; Katz, HI; Wildnauer, R; Green, B (June 1998). “An evaluation of the effect of an alpha hydroxy acid-blend skin cream in the cosmetic improvement of symptoms of moderate to severe xerosis, epidermolytic hyperkeratosis, and ichthyosis.”. Cutis61 (6): 347–350