Lactic acid is alpha hydroxy acid (AHA) that removes dead skin cells, lightens dark spots, and improves the look of fine lines and wrinkles on all skin types, including sensitive skin.

Lactic acid is used in many over-the-counter (OTC) skincare products and professional treatments. It’s also found in many products that are put on the skin (topical), as well as treatments for eczema, psoriasis, and rosacea.

Lactic acid helps remove old, dull cells on the skin’s surface by dissolving the bonds that hold them together (exfoliation).

Lactic acid also makes cell turnover happen faster and stimulates the processes by which your skin sheds old cells and replaces them with new ones (cell renewal).1

As a result, lactic acid gives you a brighter complexion as well as smoother and softer skin.

Lactic acid is popular for two main reasons:

It can create real change in the skin if used regularly.
It’s one of the gentler hydroxy acids used in skin care.
There are also some other possible benefits of lactic acid for your skin, including:

Thickens and tightens your skin
Helps clear pores
Brightens and smooths your complexion
An effective antimicrobial
Balances the microbiome of the skin for people with sensitive skin and acne
All alpha hydroxy acids exfoliate and improve skin texture, but lactic acid has an extra benefit that you won’t get from other AHAs, like glycolic acid and mandelic acid.

Lactic acid helps improve your skin’s built-in process for keeping itself hydrated (natural moisture factor).2 Basically, lactic acid helps to keep your skin moisturized and feeling less dry.

Lactic acid also helps firm up and tighten skin by exfoliating dead skin cells, encouraging new cell turnover, and stimulating a fiber that helps keep skin firm (collagen) as well as a protein that keeps skin tight (elastin).

Fading sun spots or age spots and smoothing or softening fine lines and wrinkles is another benefit of lactic acid. However, it will not improve deeper lines.

Lactic acid is a main ingredient in OTC lotions and creams for those “chicken skin” bumps on the backs of the arms (keratosis pilaris). Lactic acid helps dissolve the plug of skin cells that build up around the hair follicle and smooth out the bumpiness.