In Part 3 of a look at the chemicals in some skin care products, today's blog explains what lactic acid is, where it can be found and who should use it.
Lactic Acid
What is it? Lactic acid, another AHA, is similar to glycolic but “a little bit more gentle,” according to Greenfield. “It also is a chemical exfoliator, so it’s used if you want to brighten your skin, get rid of rough dead skin,” she said.
Lactic acid can be found in milk, which is why Cleopatra used to soak in milk baths, according to Gmyrek.
Who should use it? Gmyrek said she recommends products with lactic acid for anyone looking to treat dry, dead skin and improve hydration. It can also be used to soften the little bumps some people get on the backs of their arms, known as keratosis pilaris, she added.
Greenfield said that lactic acid, like glycolic acid, is generally well-tolerated on most skin types.
Lactic acid is said to work best at a lower pH, Emma Hobson, education manager for Dermalogica and the International Dermal Institute, told Harper’s Bazaar in 2018. She added that for at-home use, lactic acid products should be about 10 percent or less, with a pH of around 3.5 to 4. Gmyrek said you can also find some over the counter products with 12 percent lactic acid.