Castor oil is a vegetable oil that is used for a wide range of cosmetic and medical purposes. It is said to provide health benefits for the face and skin.

People typically take castor oil as a laxative, but the oil has potential benefits for the skin. Castor oil and ricinoleic acid are thought to increase absorption in the skin and are sometimes used in the treatment of various skin conditions, including dermatosis, psoriasis, and acne. There are also anecdotal reports of castor oil promoting hair growth, including eyelashes, though no scientific literature that supports this it is a traditional treatment to thicken hair around the world.