- Castor oil, referred to as "kiki" and used by the ancient Egyptians and Greeks to treat many conditions, is a vegetable oil obtained from the castor seed (Ricinus communis). The name "castor" was given to the plant by English traders who confused its oil with the oil of another shrub called "agno-casto" in Jamaica.
- Castor oil may be taken by mouth or applied to the skin or eyes. Castor oil packs, which are applied to the skin, are traditional holistic treatments for many conditions.
- Castor oil is used as a folk remedy around the world. In India, it is massaged into the breasts after childbirth to encourage milk flow. In Ayurvedic medicine, a plaster-like mixture of castor oil seeds is applied to swollen and tender joints. In China, the crushed seeds are used to treat weaken or paralyzed muscles in the face. Castor seeds have been used in traditional medicine as an oral birth control agent among tribes from Nigeria.
- When taken by mouth, clinical trials have shown that castor oil may act as a laxative or promote bowel movements before a colonoscopy or related procedures. Castor oil typically promotes bowel movement activity within 3-5 hours after ingestion. Castor oil may also induce labor in late pregnancies.
- Castor oil is thought to potentially relieve aches and strains by drawing lactic acid out of the muscles. A rub composed of hot castor oil massaged into an infant's belly has been used to relieve colic and expel intestinal gas.