Lactic acid is a popular AHA (alpha hydroxy acid) that is a gentler alternative to glycolic acid, so can even be used on sensitive skin.
It works to exfoliate skin, removing dead skin cells to reveal glowing, more even-toned, smooth skin. This also benefits acne prone skin as it removes dead skin that clogs pores. It is also known to improve hyperpigmentation, acne scars or age spots.
Lactic acid also benefits dry skin as it is a humectant meaning that it helps the skin to retain its moisture. It works to increase the natural barrier of skin's outer layer to help prevent natural oils and water from escaping.
Lactic acid has anti-ageing benefits, it helps smooth skin through exfoliation and improves skin cell turnover which promotes the production of collagen and elastin that works to firm skin and reduce the appearance of fine lines and wrinkles.