ret·i·no·ic acid noun \ˌret-ən-ˌō-ik-\
: either of two isomers of an acid C20H28O2 derived from vitamin A and used especially in the treatment of acne: a or all–trans–retinoic acid : tretinoin b or 13–cis–retinoic acid : isotretinoin
Seen & Heard
What made you want to look up retinoic acid? Please tell us where you read or heard it (including the quote, if possible).