retinoic acid

(rĕtˌn-ōˈĭk)

1. A vitamin A derivative, C₂₀H₂₈O₂, that is a regulator substance in morphogenesis and functions in the growth and development of bone and the maintenance of epithelium.
2. A preparation of this, used topically to treat acne and to modify the appearance of fine wrinkles, hyperpigmentation, and roughness of facial skin.