Why This Old-School Acne Ingredient Cleared Skin—and Why Dermatologists Still Swear By It

An older acne treatment

In the early 2000s, the writer tried salicylic acid washes, witch hazel toners, apricot scrubs and benzoyl peroxide spot treatments. Later, Proactiv offered a three-step routine that included benzoyl peroxide and an exfoliating toner.

The writer credits benzoyl peroxide with preventing breakouts, but says few new acne products highlight the ingredient. Other ingredients, including salicylic acid, tea tree oil, azelaic acid, niacinamide, sulfur, glycolic acid and lactic acid, appear more prominent in launches.

Why dermatologists value it

Heather Woolery-Lloyd, a dermatologist, says dermatologists have continued to favor benzoyl peroxide. She describes it as effective and predictable, and calls it a hero for acne. The ingredient targets bacteria involved in acne. Woolery-Lloyd explains that it releases oxygen inside pores, which breaks apart the bacteria.

How it works in pores

Acne-prone pores can accumulate oil and bacteria, creating conditions that lead to pimples. Benzoyl peroxide helps kill the acne-causing bacteria in those pores. It is also comedolytic, meaning it can gently break down dead skin cells and reduce clogged pores, Woolery-Lloyd says.

A challenge for product makers

Despite its benefits, benzoyl peroxide can be difficult to formulate into products that feel pleasant to apply. Woolery-Lloyd says it is more complicated to work with than salicylic acid. That formulation challenge may help explain why brands use salicylic acid more readily, even as dermatologists continue to regard benzoyl peroxide as a valuable acne treatment.