| PubChem = 5538 | DrugBank = APRD00362 | C=20 | H=28 | O=2 | | molecular_weight = 300.4412 g/mol | bioavailability = | protein_bound = > 95% | melting_point=180 | metabolism = | elimination_half-life = 0.5-2 hours | pregnancy_category = X | legal_status = | legal_AU = S4 | routes_of_administration = Topical, oral }} Tretinoin is the acid form of vitamin A and so also known as all-trans retinoic acid or ATRA. It is a drug commonly used to treat acne vulgaris and keratosis pilaris. It is availab… (More on Tretinoin)