Negligible penetration of incidental amounts of alpha-hydroxy acid from rinse-off personal care products in human skin using an in vitro static diffusion cell model

► 10% glycolic acid lotions reportedly increase skin damage after UV light exposure. ► Penetration of AHAs into human skin is pH-, concentration-, and time-dependent. ► We examine in vitro human skin penetration of AHAs in rinse-off products. ► Rinsing within minutes removes >99% of AHAs in rinse-off products from the skin. ► AHAs in rinse-off products likely do not increase UV-dependent skin effects.