PSA: Benzoyl peroxide is acne prevention

Most marketing for acne cream is wrong.

The majority of acne creams are based on benzoyl peroxide, which “kills acne”. Specifically, there are really two aspects to “acne”: the bacterium C. acnes, and the medical condition acne vulgaris. Left untreated, C. acnes causes acne vulgaris, aka “pimples”, “spots” or usually just “acne”.

BP works by oxidizing on the surface of the skin and killing off C. acnes. Logically, this means that BP must be applied before any acne forms.

However, that is not how most acne creams are marketed! Neutrogena, for instance, markets their On-the-Spot Acne Treatment, 2.5% BP as, well, “spot treatment”. But that is exactly the wrong framing. Spot treatment is a misnomer! By the time the acne has shown up, its too late.

Neutrogena is not alone here - there’s a whole marketing category of “spot treatments” (e.g. Oxy, 5% BP), which exists for reasons I do not understand. I suspect most people do not empirically evaluate the effectiveness of their acne treatments, or they falsely correlate the natural resolution of their spots with application of acne cream.

Either way: BP prevents acne, so the right way to use it is to apply it at all acne prone areas, before the acne has shown up. For most people this will be the whole face, and for others, the neck, ears, chest, etc.