Soriatane, also known as Acitretin, (a synthetic form of vitamin A) is the only oral retinoid approved by the FDA specifically for treating psoriasis. The specific manner in which Soriatane works to treat psoriasis is still a mystery, but in general, retinoids help regulate the rate skin cells grow and shed. The downside? It can take up to six months to see results, and you can’t take it if you’re pregnant, breastfeeding, or trying to become pregnant. It’s also strongly cautioned against if you have severe liver or kidney disease, high triglycerides or if you’re allergic to retinoids in general. To learn more about the side effects, discuss Soriatane with your physician.