Castor oil can be used as an irritant/simulative laxative. Castor oil is a natural emollient and a few drops may also be used to remedy dry skin, as a massage oil, and may benefit hair as a treatment. Castor oil contains ricinoleic acid, a fatty acid that comprises about 90% of the oil. Castor oil is a triglyceride, which chemically is a glycerol molecule with each of its three hydroxyl group esterifies with a long-chain fatty acid.