Does benzoyl peroxide counteract tretinoin gel?

No: Tretinoin and benzoyl peroxide work in different ways to control acne, but they do not counteract each other. In fact, there is a prescription medication with both ingredients in it; however, it's fine to use each one individually (and cheaper, as well).

No: No. They are often used together to treat acne, though may cause skin dryness and discomfort.