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Castor Oil

What You Need to Know About Castor Oil


Updated October 22, 2013

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Castor oil is a natural remedy derived from the castor bean (Ricinus communis). Long used in traditional medicine, castor oil is often found in lubricants and in laxatives. The main component of castor oil is ricinoleic acid, a type of fatty acid shown to possess anti-inflammatory properties.

Since castor oil can be toxic when consumed in large amounts, medical experts typically recommend using it only externally over unbroken skin.

Uses for Castor Oil

Proponents claim that castor oil offers a number of health benefits, including treatment of the following conditions:

In addition, castor oil is said to induce labor in pregnant women.

What Is a Castor Oil Pack?

A castor oil pack is created by soaking a cloth in castor oil. When placed on the skin, castor oil packs are thought to enhance circulation and promote healing of the tissues and organs underneath the skin. Some alternative medicine practitioners also use castor oil packs to improve liver function, relieve pain, reduce inflammation, and improve digestion.

Find out how to make a castor oil pack.

Benefits of Castor Oil

To date, research on the health benefits of castor oil is somewhat limited. Furthermore, the existing studies on castor oil's health effects have yielded mixed results. Here's a look at some key study findings:

1) Labor

Castor oil does not appear to induce labor, a 2009 study from the Australian & New Zealand Journal of Obstetrics & Gynaecology shows. The study involved 612 women whose pregnancy had lasted longer than 40 weeks. Of those women, 205 received castor oil for induction of labor. The study's authors found that the time to birth was not significantly different between the two groups.

2) Laxative

Castor oil packs may improve some symptoms of constipation, according to a 2011 study from Complementary Therapies in Clinical Practice. In tests on elderly patients with constipation, researchers found that seven days of treatment with castor oil packs helped reduce several constipation symptoms (such as straining during defecation). However, castor oil packs failed to have an effect on the number of bowel movements or amount of feces.

3) Hair

To date, there is no evidence that castor oil can stimulate hair growth. However, preliminary research published in the Journal of Cosmetic Science in 2003 indicates that castor oil may improve hair by increasing its luster.

4) Arthritis

Taking a castor oil supplement may be of some benefit to people with osteoarthritis of the knee, a 2009 study from Phytotherapy Research suggests. For four weeks, 50 people with knee osteoarthritis took capsules containing either castor oil or diclofenac sodium (a non-steroidal anti-inflammatory drug) three times daily. Results revealed that both treatments were significantly effective.

Where to Find Castor Oil

Castor oil can be found in drugstores, natural-foods stores, and stores specializing in dietary supplements. In addition, castor oil can be purchased online.

Castor Oil Safety Concerns

Swallowing a large amount of the oil can be harmful, according to the National Institutes of Health. Signs of castor oil overdose include:

  • abdominal cramps
  • diarrhea
  • dizziness
  • hallucinations
  • fainting
  • nausea
  • shortness of breath and chest pain
  • skin rash
  • throat tightness

Due to these safety concerns, castor oil should only be consumed after consulting a health care professional.


Arslan GG, Eşer I. "An examination of the effect of castor oil packs on constipation in the elderly." Complement Ther Clin Pract. 2011 Feb;17(1):58-62.

Boel ME, Lee SJ, Rijken MJ, Paw MK, Pimanpanarak M, Tan SO, Singhasivanon P, Nosten F, McGready R. "Castor oil for induction of labour: not harmful, not helpful." Aust N Z J Obstet Gynaecol. 2009 Oct;49(5):499-503.

McMullen R, Jachowicz J. "Optical properties of hair: effect of treatments on luster as quantified by image analysis." J Cosmet Sci. 2003 Jul-Aug;54(4):335-51.

Medhi B, Kishore K, Singh U, Seth SD. "Comparative clinical trial of castor oil and diclofenac sodium in patients with osteoarthritis." Phytother Res. 2009 Oct;23(10):1469-73.

National Institutes of Health. "Castor oil overdose: MedlinePlus Medical Encyclopedia". October 2011.

Vieira C, Evangelista S, Cirillo R, Lippi A, Maggi CA, Manzini S. "Effect of ricinoleic acid in acute and subchronic experimental models of inflammation." Mediators Inflamm. 2000;9(5):223-8.

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