Isotretinoin anti-acne drug, molecular model. Atoms are represented as spheres and are colour- coded; carbon (blue), hydrogen (white) and oxygen (turquoise). Isotretinoin, also known as roaccutane, belongs to a group of drugs derived from vitamin A, called retinoids. It acts by reducing the amount of sebum (oil) that sebaceous glands in the skin produce. Excessive production of sebum blocks the sebaceous glands and creates an ideal environment for the bacteria that cause acne. Isotretinoin is only used when other treatments, such as antibiotics, have failed. This is because of its many side effects, which include birth defects, kidney disease and possibly depression.