Story at a Glance
- Castor oil is considered one of the world’s oldest drugs, perhaps most well-known for its laxative effects and ability to induce labor in pregnant women—although I don’t recommend using it for the latter purpose.
- While castor beans have notable anti-inflammatory, anthelmintic, antibacterial, wound-healing, and laxative properties, they also contain ricin, a poison; fortunately, ricin isn’t found in castor oil.
- Castor oil packs may help relieve symptoms of constipation in older people; the U.S. Food and Drug Administration (FDA) considers castor oil as “generally regarded as safe and effective” for use as a stimulant laxative.
- Topical application of ricinoleic acid found in castor oil may exert “remarkable analgesic and anti-inflammatory effects,” including relief from muscle and joint pain.
- Castor oil may be useful for fungal diseases, skin health, dry eye, and other eye surface diseases.
In Prehistoric Times, Castor May Have Been Used as a Poison
While castor beans have notable anti-inflammatory, anthelmintic, antibacterial, wound-healing, and laxative properties, they also contain ricin, a poison. This is why, if chewed and swallowed, castor beans are toxic. While ricin is also contained in the bean pulp that remains after it’s pressed for oil, it isn’t found in castor oil.“The castor plant has been known since time immemorial and its use in the prehistoric era has been evidenced by archaeological findings such as that of the Border Cave in South Africa. Traces of wax containing ricinoleic and ricinelaidic acids were found on a thin wooden stick, which was suggested to be a poison applicator, dating back to about 24,000 years ago.”
Ricin prevents protein synthesis and kills your cells through oral, nasal, or intravenous transfusion. It’s so potent that ingesting or inhaling just 1 milligram may be fatal,6 just as eating four to eight castor seeds can lead to death.7 There is no antidote for ricin, which is why it’s even used as a chemical warfare agent. In 2013, there were reports of ricin being mailed to U.S. senators and even former President Obama.8Castor Oil Used ‘Since Time Immemorial’
Castor bean has a number of beneficial properties that have been harnessed since ancient times. “The castor plant (Ricinus communis L.) has been known since time immemorial in traditional medicine in the pharmacopeia of Mediterranean and eastern ancient cultures. Moreover, it is still used in folk medicine worldwide,” University of Bologna, Italy, researchers wrote in the journal Toxins.9- The Hearst Papyrus describes castor plant for expelling fluid accumulation and use in poultices for bandaging.
- Ancient Egyptians used the castor plant for urinary disease in a possibly diabetic child.
- Hippocrates prescribed castor oil as a laxative and detoxifying agent.
- The Greek herbalist and physician Pedanius Dioscorides wrote about castor seeds’ expectorant, diuretic, emetic, laxative, and anti-inflammatory properties to treat burns, varicose veins, and bacterial skin infections.
- Pliny the Elder described castor bean in “Naturalis Historia” (Natural History), which is considered the first encyclopedia.
10 Modern-Day Uses for Castor Oil
While it’s long been known that castor oil acts as a laxative and labor inducer, it was relatively recently—in 2012—when researchers found the mechanism behind it. It turns out that ricinoleic acid in castor oil connects to a prostaglandin receptor known as EP3.Oral ingestion of castor oil can “purge” the digestive tract within two to five hours. However, remember to take it in the appropriate dose. Adults can take 1 to 2 tablespoons, while children 2 to 12 years old should be given only 1 to 2 teaspoons. Infants under 2 years old are not advised to take more than 1 teaspoon at a time. When giving it to children, try mixing it in freshly squeezed juice so it becomes more palatable.
In addition to offering a moisturizing effect on hair, the fatty acids in castor oil may nourish the hair follicle. Ricinoleic acid also helps protect the scalp and hair shaft from fungal and microbial infections. It also penetrates the skin and may inhibit prostaglandin D2 synthase, which inhibits hair growth.
To get this effect, warm 1 tablespoon of the oil and use your fingertips to coat each strand, running your fingers through your locks to get it on as much hair as possible.
If your pet licks the wound (as most pets do), the oil is not harmful but could lead to loose stools.
Among infants, castor oil is also sometimes used for colic, which can lead to long periods of excessive crying. Its exact cause is still unknown, although gas is believed to be a major culprit. To use castor oil for colic, simply rub it gently on your child’s abdomen.
“Evidence of beneficial effects on the lipid layer, tear film integrity, eyelash health and meibomian gland functionality, suggests that topical application of pure castor oil to the periocular skin may offer a safe, natural, affordable and effective management option for common abnormalities of the tear film and ocular surface, indicating that a more extensive and thorough exploration of this topic is warranted.”10. All-around lubricant: If you have items around your home that need lubrication, such as squeaky hinges, scissors, or meat grinders, castor oil works perfectly for these problems. Due to its consistent viscosity, castor oil does not freeze, so it can be used in conditions with hot or very cold temperatures.
Castor Oil Risks to Watch Out For
Pregnant women shouldn’t use castor oil due to its ability to induce contractions. Even late in pregnancy, I don’t recommend using castor oil to stimulate labor. One study reported that all pregnant women who took castor oil experienced nausea afterward.26Further, as with any herbal oil, I recommend you use castor oil with care, as it can have potentially negative side effects. Those with sensitive skin may experience allergic reactions when using this oil topically, which is why I advise doing a skin patch test prior to applying it copiously on large skin areas.
If taken internally, castor oil may also lead to gastrointestinal upset and discomfort, as well as dizziness and nausea. So if you suffer from any digestive problems like irritable bowel syndrome, ulcers, cramps, diverticulitis, colitis, or hemorrhoids, I advise you to avoid using this oil. Those who have recently undergone surgery should also refrain from using castor oil.
Lastly, make sure that you purchase organic castor oil from a reputable source. Commercial castor oil sold in stores today often comes from castor seeds that were likely heavily sprayed with pesticides or processed with solvents and other chemical pollutants, which damage its beneficial components and may even contaminate the oil.
◇ References
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- 5, 9 Toxins (Basel). 2019 Jun; 11(6): 324
- 6 Cornell University, Ricin Toxin from Castor Bean Plant, Ricinus communis
- 7 American Journal of Emergency Medicine, 1986 May;4(3):259-61
- 8 Popular Science, April 18, 2013
- 10, 11 Toxins (Basel). 2019 Jun; 11(6): 324, Castor Bean in Traditional and Folk Medicine
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- 21 National Library of Medicine, StatPearls, Moisturizers, Types of Moisturizers
- 23 BMC Complement Altern Med. 2016; 16: 211
- 24 J Wound Ostomy Continence Nurs. 2005 May-Jun;32(3):163-70. doi: 10.1097/00152192-200505000-00004
- 25 Clinical and Experimental Optometry October 9, 2020
- 26 The Cochrane Database of Systematic Reviews, 2001;(2):CD003099
- 27 Journal of Biology, Agriculture and Healthcare, 2014 4:(4)