Tretinoin, by Janssen Cilag. What is Retin A? Retin-A is brand name of the generic drug Tretinoin. Retin-A is used in the treatment of acne. It is prescribed to treat acne vulgaris on facial skin. Retin A is made from vitamin A, a fat-soluble vitamin that is absorbed through the intestines and stored in the liver. Vitamin A is important to maintaining healthy skin, mucous membranes, the intestinal lining, organs, immune system and the suppression of tumor growth.

Isotretinoin, by Roche. Accutane is a powerful drug approved by the FDA for the treatment of resistant or scarring acne. When taken for 20 weeks, Accutane has a greater than 85% rate of clearing patients' acne for at least one year, and in many cases, permanently. All other effective acne medications can control acne, but the acne returns then treatment is stopped.

Effective dosage: The recommended dosage range for Accutane is 0.5 to 2 mg/kg given in 2 divided doses daily for 15 to 20 weeks.