Lactic Acid

Lactic acid is a chemical exfoliant that increases cell turnover and eliminates dead skin cells. It also hydrates the skin, resulting in firmer and smoother looking skin. Lactic acid comes from the fermentation of lactose, a milk carbohydrate, which explains why Cleopatra bathed in sour milk to keep her youthful-looking skin.

Aside from achieving a smoother complexion, lactic acid also has anti-microbial properties and works well in treating blemishes.