It takes around 28 days for the skin’s natural exfoliation cycle to finish, a process known as desquamation. While chemical exfoliants, like lactic acid, will aid the process, it still takes time.
"As a result, lactic acid tends not to penetrate deeply in the skin, making it a more gentle exfoliating acid." Corey L. Hartman, MD, FAAD, board-certified dermatologist and founder of Skin ...
“Exfoliation can offer several benefits for ... If PHAs aren’t the route you want to go down, lactic acid is another option. Technically, it’s an AHA but far milder, making it more tolerable.