Castor bean (Ricinus communis)

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • Aceite de ricino (Spanish), AllanDerm-T™, asiixa’a (Nahuatl), castor oil, castor seed, Cremophor EL™ (CrEL™), Cremophor RH40 (AquaLub™), Emulsoil®, Euphorbiaceae (family), Fleet Castor Oil®, Granul-derm™, Granulex®, hydrogenated castor oil (Cutina® HR), kiki, lemon-flavored castor oil (Purge®), linoleic acid, Mexico seed, mole bean, oleic acid, Optase™, Palma Christi (Spanish), polyoxyl 35 castor oil, polyoxyl 40 hydrogenated, Revina™, ricin, ricino (Spanish), ricinoleic acid, Ricinus communis, RICOM-1013-J, undecylenic acid, xcoch (Mayan), Xenaderm™.

  • Select combination products: AllanDerm-T™, Granul-derm™, Optase™, Revina™, Trypsin Complex, Xenaderm™, Balsa-Derm®, Granul®, and Granulex® are brand names for a topical spray composed of trypsin, balsam of Peru, and castor oil.

Background

  • 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.

Scientific Evidence

Uses

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Bowel cleansing

Early evidence has shown that a single dose of castor oil given by mouth may help cleanse the bowels. Some research suggests that castor oil is more effective at causing bowel movements than a high-fiber diet or milk of magnesia and cascara. There is disagreement about whether castor oil is better than a commercial kit composed of magnesium citrate oral solution, phenolphthalein, and bisacodyl.

Childbirth (labor induction)

Early evidence suggests that castor oil may promote cramping of the intestines and uterus, causing labor in late pregnancies when taken by mouth. Its activity may be as effective as oxytocin but with fewer associated risks. Limited research suggests that leakage of amniotic fluid into the mother’s bloodstream and signs that the baby has had a bowel movement while still inside the womb may occur after taking castor oil by mouth. Further studies are needed before conclusions are made.

Colonoscopy preparation

Early evidence suggests that castor oil may help prepare the digestive systems for a radiological exam, endoscopy, or colonoscopy. Some research suggests that although a single dose of castor oil given by mouth may be effective, its oily texture, unpleasant taste, and adverse effects limit its appeal. Additional research is needed in this area before a strong conclusion can be made.

Dry eyes

Limited research suggests that applying eyedrops made from castor oil and water may promote tear formation and reduce tear evaporation for individuals with dry eye. Additional research is needed in this area before a strong conclusion can be made.

Birth control

Castor seeds have been used in traditional medicine as an oral form of birth control among tribes in Nigeria. Further research is needed before a firm conclusion can be made.

*Key to grades:

Tradition

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

  • Abscess (pus collection), arthritis (joint swelling), breast cancer, bruises, cancer, cathartic (promotes bowel movements), cervical cancer, cholecystitis (swelling of the gallbladder), colds, colic, colitis (swelling of the large intestine), congestion, constipation, corns, cosmetic, cough, cystitis (swelling of the bladder), dermatitis (skin inflammation), dry skin, enema, epilepsy (seizures), facial palsy (weakness of facial muscles), fever, gastrointestinal disorders (appendicitis), headache, hypogonadism (reduced hormones production), inflammation, lactation (breastfeeding), liver conditions, lymph flow enhancement, muscle ache, neuritis (nerve inflammation), pain, painful joints, poisoning, promotion of digestion, ringworm, scleroderma (immune disorder that affects connective tissue), skin conditions (general), sprains and strains, sunburn, ulcer, uterine cancer, warts, wounds.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

  • For most conditions, 15-60 milliliters of castor oil has been given by mouth.

  • For bowel cleansing, a single dose of 30-80 milliliters of castor oil with water has been used.

  • To prepare for a colonoscopy, 60 milliliters of castor oil has been taken by mouth the night before the examination, with only water to be consumed afterwards.

  • For birth control, castor seeds, weighing 2.3-2.5 grams, have been given as a single oral dose with water after 4-5 days of menstruation.

  • To cause childbirth, a single 60-milliliter dose of castor oil has been taken by mouth.

  • To reduce inflammation of the eyelash follicles, castor oil has been applied over the eyelashes and eyelids at least 3-4 times daily for one week.

  • For conjunctivitis, 1-2 drops of castor oil have been applied to the eyes twice daily for three days.

  • For dry eyes, eyedrops containing a castor oil and water mixture have been used three times daily for 30 days.

  • For eye styes, two drops of castor oil in the affected eye 3-4 times daily for two days have been used.

Children (under 18 years old)

  • Consult a physician before giving castor oil to children. Use in children for occasional constipation is generally avoided.

  • For children under two years old,1.25-7.5 milliliters of castor oil by mouth has been used.

  • For children 2-11 years old, 5-15 milliliters of castor oil by mouth has been used.

  • For children over 11 years old, 15-60 milliliters of castor oil by mouth has been used.

  • For colic in infants, a hot castor oil rub massaged into an infant’s belly has been used.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

  • Avoid in individuals with a known allergy or sensitivity to the castor bean, castor oil, or other members of the family Euphorbiaceae.

Side Effects and Warnings

  • When taken by mouth, castor oil may cause abdominal cramps, abnormal heartbeat, alkalosis (pH imbalance), drowsiness, anorexia, burping, colon irritation, constipation, diarrhea, dizziness, fainting, fluid or electrolyte imbalance, gas, headaches, increased pain from menstrual cramps, insomnia, lack of coordination, leakage of amniotic fluid into a pregnant woman’s bloodstream, low potassium levels, muscle cramps, nausea, permanent nerve damage, vomiting, and weakness.

  • When applied to the skin, castor oil may cause skin irritation; stinging; rash; itching; hives; swelling of the face, lips, or tongue; and bleeding or redness. Castor oil may also interact with other skin products.

  • When used as an eyedrop, castor oil may cause blurred vision.

  • Use cautiously in individuals who drive or operate heavy machinery, individuals wearing contact lenses, individuals taking agents that affect electrolytes, individuals taking fat-soluble vitamins, individuals taking agents that affect the immune system, individuals taking agents that affect p-glycoprotein modulators, and individuals taking digoxin.

  • Use cautiously in individuals taking agents that affect blood pressure, as castor oil may increase blood pressure when taken by mouth.

  • Use cautiously in breastfeeding women, as castor oil may leak into breast milk when taken by mouth.

  • Avoid use of unprocessed castor seeds or beans, as they may be toxic when touched or taken by mouth.

  • Avoid repeated castor oil use, due to the risk of dehydration and laxative dependence when taken by mouth.

  • Avoid use in pregnant women, due to the risk of causing labor when taken by mouth.

  • Avoid using by mouth in patients with signs of appendicitis or any gastrointestinal disorders.

  • Avoid taking other medications or herbs and supplements within two hours of taking castor oil by mouth.

  • Avoid in individuals with a known allergy or sensitivity to the castor bean, castor oil, or other members of the family Euphorbiaceae.

Pregnancy and Breastfeeding

  • Avoid in pregnant women, due to the risk of causing labor.

  • Use cautiously in breastfeeding women, as castor oil may be leaked into breast milk when taken by mouth.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

  • Castor oil may increase blood pressure. Caution is advised in patients taking agents that affect blood pressure.

  • Castor oil may also interact with agents that affect the immune system, agents that regulate p-glycoprotein activity, anti-inflammatory agents, birth control agents, digoxin, diuretics (agents that control electrolyte levels), droperidol, laxatives, levomethadyl, painkillers, and silver sulfadiazine.

Interactions with Herbs and Dietary Supplements

  • Castor oil may increase blood pressure. Caution is advised in patients taking herbs and supplements that affect blood pressure.

  • Castor oil may also interact with anti-inflammatory herbs and supplements, birth control herbs and supplements, cardiovascular herbs and supplements, diuretics (herbs and supplements that control electrolyte levels), fat-soluble vitamins, herbs and supplements that affect the immune system, herbs and supplements that regulate p-glycoprotein activity, laxatives, and painkillers.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Allaire, A. D., Moos, M. K., and Wells, S. R. Complementary and alternative medicine in pregnancy: a survey of North Carolina certified nurse-midwives. Obstet.Gynecol. 2000;95(1):19-23. View Abstract
  2. Azhari, S., Pirdadeh, S., Lotfalizadeh, M., and Shakeri, M. T. Evaluation of the effect of castor oil on initiating labor in term pregnancy. Saudi.Med J 2006;27(7):1011-1014. View Abstract
  3. Chen, C. C., Ng, W. W., Chang, F. Y., and Lee, S. D. Magnesium citrate-bisacodyl regimen proves better than castor oil for colonoscopic preparation. J.Gastroenterol.Hepatol. 1999;14(12):1219-1222. View Abstract
  4. Di Pascuale, M. A., Goto, E., and Tseng, S. C. Sequential changes of lipid tear film after the instillation of a single drop of a new emulsion eye drop in dry eye patients. Ophthalmology 2004;111(4):783-791. View Abstract
  5. Final report on the safety assessment of Ricinus Communis (Castor) Seed Oil, Hydrogenated Castor Oil, Glyceryl Ricinoleate, Glyceryl Ricinoleate SE, Ricinoleic Acid, Potassium Ricinoleate, Sodium Ricinoleate, Zinc Ricinoleate, Cetyl Ricinoleate, Ethyl Ricinoleate, Glycol Ricinoleate, Isopropyl Ricinoleate, Methyl Ricinoleate, and Octyldodecyl Ricinoleate. Int J Toxicol. 2007;26 Suppl 3:31-77. View Abstract
  6. Garry, D., Figueroa, R., Guillaume, J., and Cucco, V. Use of castor oil in pregnancies at term. Altern.Ther.Health Med. 2000;6(1):77-79. View Abstract
  7. Gray, M. and Jones, D. P. The effect of different formulations of equivalent active ingredients on the performance of two topical wound treatment products. Ostomy.Wound.Manage. 2004;50(3):34. View Abstract
  8. Goto, E., Shimazaki, J., Monden, Y., Takano, Y., Yagi, Y., Shimmura, S., and Tsubota, K. Low-concentration homogenized castor oil eye drops for noninflamed obstructive meibomian gland dysfunction. Ophthalmology 2002;109(11):2030-2035. View Abstract
  9. Khanal, S., Tomlinson, A., Pearce, E. I., and Simmons, P. A. Effect of an oil-in-water emulsion on the tear physiology of patients with mild to moderate dry eye. Cornea 2007;26(2):175-181. View Abstract
  10. Kolts, B. E., Lyles, W. E., Achem, S. R., Burton, L., Geller, A. J., and MacMath, T. A comparison of the effectiveness and patient tolerance of oral sodium phosphate, castor oil, and standard electrolyte lavage for colonoscopy or sigmoidoscopy preparation. Am.J.Gastroenterol. 1993;88(8):1218-1223. View Abstract
  11. Mitri, F., Hofmeyr, G. J., and van Gelderen, C. J. Meconium during labour–self-medication and other associations. S.Afr.Med J 4-4-1987;71(7):431-433. View Abstract
  12. Palese, A., Clementi, R., and Busetti, R. [Variability of intestinal preparation in patients undergoing stomach, intestine, uterus surgery at 4 hospitals]. Assist.Inferm.Ric. 2003;22(1):13-18. View Abstract
  13. Pearce, E. I., Tomlinson, A., Blades, K. J., Falkenberg, H. K., Lindsay, B., and Wilson, C. G. Effect of an oil and water emulsion on tear evaporation rate. Adv.Exp.Med Biol. 2002;506(Pt A):419-423. View Abstract
  14. Scarpa, A. and Guerci, A. Various uses of the castor oil plant (Ricinus communis L.). A review. J.Ethnopharmacol. 1982;5(2):117-137. View Abstract
  15. Steingrub, J. S., Lopez, T., Teres, D., and Steingart, R. Amniotic fluid embolism associated with castor oil ingestion. Crit Care Med. 1988;16(6):642-643. View Abstract

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.