Benzoyl Peroxide

Among over the counter acne treatments, benzoyl peroxide is widely considered the most effective antibacterial option available. It works by releasing active oxygen on contact with skin, which is toxic to acne causing bacteria, and unlike some other treatments, it does this without contributing to antibiotic resistance. It's also able to penetrate directly into the hair follicle, reaching bacteria at the source with a relatively low risk of irritation.

You might expect an antibacterial ingredient this strong to throw off skin's microbiome, the balance of microorganisms that shapes how skin looks and functions, but research actually shows the opposite. By keeping P. acnes bacteria in check, benzoyl peroxide helps maintain that balance rather than disrupt it.

Formulas range in strength from 2.5% to 10%, and it's generally best to start low. A 2.5% concentration tends to be just as effective as 5% or 10%, with noticeably less irritation. It's also considered generally safe during pregnancy and breastfeeding, since very little of it is absorbed into the body.