Category: topical
Aliases: Retin-A, Renova, Retacnyl, all-trans retinoic acid, ATRA
All-trans retinoic acid — binds nuclear retinoic-acid receptors (RAR-α/β/γ) directly, without requiring metabolic activation. Normalises follicular keratinisation (comedolysis), accelerates epidermal turnover, thickens viable epidermis, thins stratum corneum, disperses melanin, and upregulates dermal collagen I/III while down-regulating MMP-1 under UV stress. Gold-standard topical for photoaging and a cornerstone of acne regimens. Systemic absorption <2% at labelled use; does not meaningfully alter endogenous retinoid plasma pools.
TD: 1h