How Does Benzoyl Peroxide Work?

Benzoyl peroxide is an acne medication that can be found over-the-counter or by prescription. When you apply it to your skin, it breaks down into benzoyl radicals and benzoic acid. 

Benzoyl radicals are a type of free radical that create oxygen in your skin. The bacteria that cause acne (c.acne) prefer an oxygen free environment (which is why they only really become an issue when your pores are clogged).

No oxygen = Increased c.acnes growth

By releasing free oxygen radicals in this way, benzoyl peroxide is able to kill the acne-causing bacteria in your skin.

Benzoic acid is thought to work in a similar way to salicylic acid and helps to exfoliate and unclog your pores.

Benzoyl peroxide may also target the inflammatory immune cells in your skin which prevents them from releasing the inflammatory molecules that can make acne look red and angry and sometimes feel painful.

Overall, benzoyl peroxide is:

• Anti-inflammatory
• Exfoliating
• Oil controlling

However, it’s generally considered to be less effective at treating acne than retinoids and salicylic acid unless it’s combined with other ingredients.

Because it produces free radicals, benzoyl peroxide has been shown to deplete your skin levels of vitamin E, so using it alongside an antioxidant serum or moisturizer is recommended.  ex. mandelic acid

(Note that there is no evidence to suggest that the free radicals produced by benzoyl peroxide contribute to skin aging – there is also no evidence that they don’t but the anti-inflammatory effect of benzoyl peroxide may have anti-aging benefits)