From glycolic to salicylic, exfoliating acids have quickly become a mainstay in our beauty routines. But lactic acid seems to be the lesser known of the bunch, despite being a dermatologist’s favorite ...

When I first heard about using lactic acid for skin, I had a moment of confusion—isn't that what builds up in your muscles during a workout and causes soreness later? Turns out: more or less, yes! I ...