The active ingredient in most Proactiv products is benzoyl peroxide, most often used to treat acne. Wherever you develop acne, the existence of a sebaceous follicle is the root of the acne. If any Proactiv works for your face, then it will most likely work for your body, as it's the ingredient in Proactiv, benzoyl peroxide, that is successfully treating your acne.

On the Other: If It Works, It May All Work

If the benzoyl peroxide in Proactiv clears your body acne, then any product with benzoyl peroxide may produce equally satisfying results as long as the strength (2.5%, 5%, etc.) remains the same. With Proactiv being one of the most expensive benzoyl peroxide products available in the acne treatment industry, it may be economical and beneficial to consider other acne treatments that contain the same amount of benzoyl peroxide.

Bottom Line

Proactiv is a 3 to 5 step solution that treats facial acne, and when it works, it produces excellent results for people. In theory, it works just as well on body acne. Proactiv has also produced a body wash that is intended for body use only, focused on problem areas on the body like the neck and back.

Source:

Acne.org: Body Acne

Acne Skin Tips: Washing Away Your Acne

Get Rid of Things: How to Get Rid of Body Acne

Resource:

Proactiv: About Proactiv Solution