The Complete Guide to Benzoyl Peroxide and Its Acne-Fighting Powers

Beautiful woman with glowy skin and cream on her cheekbone standing in front of white background

Think back to your first-ever breakout — most likely circa age 12 or 13, and probably very stressful. When you noticed preteen acne forming on your skin, what did you reach for? Whether you took to the drugstore aisles yourself or relied on whatever your older sibling had lying around, chances are you used something — a cleanser, scrub, spot treatment, or cream — that contained benzoyl peroxide.

This skin-care ingredient isn’t new or trendy, but that’s part of what makes benzoyl peroxide so powerful: It’s reliable. As New York City–based dermatologist Marisa Garshick puts it, benzoyl peroxide is “an oldie but goodie, in that it is an effective way to treat acne.”

But how, exactly, does benzoyl peroxide work when it applied to the skin? And what types of acne does it work best at treating? For a full rundown of the ingredient, we consulted the experts to help break down everything about benzoyl peroxide.

What is benzoyl peroxide and how does it work on skin?

Technically speaking, benzoyl peroxide is “an organic peroxide that acts as a nonspecific oxidizing agent,” explains Kimberly Jerdan, a dermatologist in California. In other words, it’s a chemical compound that, through oxidizing activity on the skin, can help treat acne.

What does oxidizing activity mean, exactly? Benzoyl peroxide is actually similar in structure to hydrogen peroxide “in that it is a peroxide type of medication that releases oxygen on the skin to destroy bacteria,” explains Florida-based dermatologist Matthew Elias. However, the ingredient works slightly differently from hydrogen peroxide (which is that clear liquid in everyone’s medicine cabinet that your parents likely applied onto cuts and scrapes when you were younger).

In addition to its ability to destroy bacteria, benzoyl peroxide is also an anti-inflammatory and comedolytic, meaning that it simultaneously works to open up pores and decrease inflammation on the skin. Pretty neat, right?

New York City dermatologist Jessica Krant sums it up best: “Benzoyl peroxide is so effective and reliable for acne because it works via several different mechanisms at once,” she tells Allure. “It is both antimicrobial, killing bacteria and other organisms, and an exfoliant, helping to unclog pores and gently debride the surface layer of skin.” So, there you have it: antimicrobial, plus anti-inflammatory, plus exfoliant, equals a powerful acne-fighting ingredient.

The ingredient’s ability to squash acne-causing bacteria in its tracks is especially important because it means that, in some cases, it can be used to tame acne in place of antibiotics. And we all know what happens when antibiotics are used for too long: resistance. Using benzoyl peroxide, either in place of or in combination with antibiotics, helps to mitigate the issue.

“The benefit of using [benzoyl peroxide] is that you don’t have to rely on an antibiotic to keep the bacteria load on the face down, and this helps reduce the risk of antibiotic resistance,” Jerdan explains.