Ricinus communis

Ricinus communis L. (Euphorbiaceae)

Castor Oil Plant, Castor Bean

Ricinus communis L. is an erect herb, growing up to 3.6 m high, having pinkish succulent stem and large alternate palmate leaves that are green or reddish brown. Leaves are lobed, consisting of 6-8 radiating leaflets with serrated edges and prominent central veins. Flowers are green, pink or red and inconspicuous, with no petals. The fruits are capsular, with three lobes, prickly and green, containing three seeds.


Native to Africa, naturalised throughout tropics and subtropics.


Ricin, ricinoleic acid, ricinine, p-coumaric acid, ferulic acid, o-coumaric acids, syringic acid, cinnamic acids, stigmasterol, fucosterol and others.

Traditional Medicinal Uses

Its leaf poultice is applied to boils and sores in India; to treat headaches and fever in Hawaii. The leaves and roots are used in a decoction for anal prolapse, arthritis, constipation, facial palsy, lymphadenopathy, strabismus, uteral prolapse, cough, and also as a discutient and expectorant. The heated leaves are applied to gout and swellings as well. The leaves and oil are used for dermatological purposes in Nigeria. Its seeds are used to treat abscesses and skin eruptions, deafness, headache, skin problems, bleeding, constipation, boils, piles and to promote labour. They are rubbed on the temple for headache, powdered for abscesses, boils, and carbuncles. The plant is also used for dogbite, scrofula and several skin infections. The Chinese rub the oil on the body for skin ailments. The seeds are crushed and made into a pulp and rubbed into the palms for palsy, introduced into the urethra in stricture and rubbed on the soles of feet of parturient woman to hasten birth or expulsion of the placenta. The seeds are also used to treat colic, diarrhoea, dysentery, enteritis, acute constipation, for itching, ringworms, warts, dandruff, hair loss and haemorrhoids. It is also used as a laxative before X-ray examination of bowels. Midwives sometimes use castor oil to induce labour.

Pharmacological Activities

Antifertility, Antioxidant, Antipsychotic, Antiviral, Anti-inflammatory, Convulsant, Hepatoprotective, Filaricidal, Haemaglutination and Insecticidal.


For internal use in the treatment of constipation or to expel worms, at least five 2 g capsules or ten 1 g capsules are recommended. Externally, a paste made of ground seeds may be applied to affected skin areas 2 times daily, up to 15 days. Homeopathically, 5 drops, 1 tablet or 10 globules are recommended every 30-60 min for acute treatment or 1-3 times daily for chronic cases. Standard adult dose is reported to be 5.0-20.0 ml/dose, not exceeding 60.0 ml per day. Standard child dose is reported to be 4.0-12.0 ml/dose. The seed oil is recommended for use as a laxative in a dose of 2 to 5 ml and as a purgative in a dose of 20 to 30 ml. 15 seeds may be crushed and applied to the plantar surface of the feet for the induction of labour at term and placenta delivery in cases of placenta retention. The woman’s feet are advised to be thoroughly washed after delivery of foetus and placenta. For constipation, it is reported that 15 to 60 ml of castor oil may be taken orally a day.

Adverse Reactions

Gastric irritation, nausea, vomiting, colic, and severe diarrhoea may occur. Long term use may result in loss of electrolytes, especially potassium, and causes intestinal motility inhibition.


Seeds are highly poisonous due to the toxic lectins, principally the albumin and ricin. The seeds are toxic to both animals and humans.


Not to be taken by children under 12 years of age, patients with acute inflammatory intestinal diseases, inflammatory bowel disease and appendicitis, contraindicated in pregnancy, intestinal obstruction and abdominal pain. Not to be given with potentially toxic oil-soluble anthelmintics.

Drug-Herb Interactions

Effect of cardioactive steroids may be increased. To prevent decreased absorption of castor, it is advised not to take within one hour of antacids, other drugs and milk.