Does the use of tretinoin on the skin cause dark spots?

With exposure: It is strongly advised that you use any products with tretinoin at night and wear sun block during the day. This medicine causes sensitivty to the sun and could cause some skin darkening/ spots. If you have dark to deep pigmentation and some acne marks already, the combo of sun and treinoin can cause more darkening of the areas. Wear your sun block and use other sources of protection.

Usually cures them: Unless you are causing burns or excessive irritation and are prone to post-inflammatory hyper-pigmentation, the use of retinoids usually improves dark spots, on occasion this is combined with topical steroids, hydroquinone, and kojic acid.