What Is It?
Isotretinoin is a vitamin A derivative called a retinoid that is taken orally and is approved only for severe acne. It is thought to clear acne primarily through its ability to permanently reduce skin oil (sebum) production.
Efficacy
Strength of Evidence
Average 87% reduction in acne after 18 weeks
Side Effects
High
High side effects and adverse reactions
Acne.org's Real World Take
The nuclear option. It works reliably and provides long-term remission of acne, and even severe acne, in about ⅔ of people who properly take an adequate dosage. However, it permanently and irreversibly changes the skin and the body forever and users may experience long-term side effects for the rest of their lives. It’ll nuke it, but there is no going back.