Keep in mind that, while over-the-counter formulas are generally gentler than medical-grade mixtures, AHAs can still be super potent, which is why Deveny says gradually introducing glycolic acid into your at-home routine is essential. "I always recommend starting by using products every other night, or spacing out days, before daily use," she says. You should also be aware of tingling and dryness that might occur after introducing acids. "When you first start using glycolic acid at home, you may experience a slight tingling during the first few days of application," Deveny says. "This will go away as your skin adjusts."