Topical retinoids, although not bleaching agents, can assist in reducing hyperpigmentation as they accelerate skin exfoliation and thus result in scattering of excess pigment. For significant darkening a bleaching or brightening agent must be used.
Will 1% Tretinoin Cream Lighten Skin Colour?
Doctor Answers 2
Tretinoin as a skin lightener
Tretinoin cream will help to speed up cell turnover, improve the overall complexion of the skin and promote new collagen resulting in less fine lines and wrinkles. A bleaching agent such as hydroquinone cream can lighten the skin after weeks to few months usage.