Castor oil, both regular one, and the Jamaican one are heavy in texture, this feature makes this oil suitable to treat small and mild acne. Also, this oil is a natural astringent that cleanses skin. The triglyceride fatty acids in castor oil are anti-viral, so they kill the bacteria that cause acne. The undecylic acid in castor oil disinfects skin and kills bacteria that cause acne and also removes clogged dead skin cells. Gently massage a few drops of castor oil to freshly cleansed affected areas. Leave for an hour and rinse with cool water. Repeat twice for better results.