You're totally right! Sunscreen is indeed regulated by the FDA, but things like acid serums, exfoliators, creams, cleansers, and lotions are not.

Our concerns about lack of regulation are two-fold: (1) That products that contain very mild ingredients (like fruit extracts) are being sold to people with claims that are unsubstantiated. For example: Claiming to reduce dark spots, when there is little scientific evidence to support it. (2) That products with very harsh ingredients (25% AHA / BHA peels, for example) are being sold without much warning and education that they could cause irritation on certain skin types.