Considered the most effective over-the-counter choice for a topical antibacterial agent in the treatment of blemishes (Source: Skin Pharmacology and Applied Skin Physiology, September–October 2000, pages 292–296). The amount of research demonstrating the effectiveness of benzoyl peroxide is exhaustive and conclusive (Source: Journal of the American Academy of Dermatology, November 1999, pages 710–716). Among benzoyl peroxide’s attributes is its ability to penetrate into the hair follicle to reach the bacteria that cause the problem, and then kill them—with a low risk of irritation. It also doesn’t pose the problem of bacterial resistance that some prescription topical antibacterials (antibiotics) do (Source: Dermatology, 1998, volume 196, issue 1, pages 119–125). Current research shows benzoyl peroxide is more effective than some other prescription treatments for acne, such as oral antibiotics or topical antibiotics (Source: Lancet, December 2004, pages 2188–2195).
Benzoyl peroxide solutions range in strength from 2.5% to 10%. It is best to start with lower concentrations because a 2.5% benzoyl peroxide product is much less irritating than a 5% or 10% concentration, and it can be just as effective. The concentration that is required depends entirely on how stubborn the strain of bacteria in your pores happens to be.