Castor Bean Oil has been therapeutically used for thousands of years by ancient cultures. Castor beans have been found in ancient Egyptian tombs and the oil from castor beans have been used in many traditional remedies for many centuries. Now we find research to back up some of this history.
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| Castor Bean Tree (Ricinus communis) |
What is Castor Bean?
The castor plant (Ricinus communis) grows in many parts of the world and tends to grow in tropical or desert climates. Its six-starred leaves with pointy seed hulls are often seen in the southwestern U.S., throughout Africa and Asia.
Castor bean plant is native to southeastern Mediterranean Basin, Eastern Africa, and India. Today it is widely cultivated and naturalized in tropical and subtropical regions worldwide.
This plant is a fast-growing perennial shrub, but often treated as an annual in cooler climates. It can reach 2–5 m tall under suitable growing conditions.
Castor bean plants have large, hand-shaped leaves and solitary male and female flowers on the same plant. They have distinctive prickly seed capsules containing 3 seeds each. Its seeds are oval-shaped, usually mottled or spotted
One of the castor bean’s central ingredients is ricin, which is toxic if eaten in significant quantities. For children, even a seed or two can cause immediate sickness and even death. Ricin poisoning will cause nausea, cramping, internal bleeding, vomiting and liver and kidney damage.
Ricin is a highly toxic glycoprotein. Even a few castor seeds chewed raw can be fatal if ingested. Raw seeds and plant sap can cause allergic reactions, rashes, or allergic asthma.
At the same time, the juice from leaves of the castor plant can be highly therapeutic when applied correctly. Traditional herbalists have used castor juice for headaches, inflammation, warts and ringworm. This use has not been confirmed by research.
In no case should a person consume castor oil without the supervision of a doctor.
Castor bean oil for massage therapy is another matter altogether. Castor bean oil processors will typically only leave trace amounts of ricin in the oil. Castor oil has been used externally for many years by general physicians and folk healers alike.
Primary Compounds in Castor Oil
Ricinoleic Acid: The primary active component, making up about 90% of the fatty acid content in castor oil.
Oleic Acid: A monounsaturated fatty acid that contributes to its moisturizing properties.
Linoleic Acid: An essential fatty acid with anti-inflammatory and skin-soothing properties.
Palmitic Acid: A saturated fatty acid that provides emollient properties.
Stearic Acid: Contributes to the consistency of the oil.
Traditional and Ethnomedicinal Uses
For thousands of years, Castor Bean oil has been used therapeutically:
Traditional Chinese Medicine
Employed in TCM for its laxative and labor-inducing properties.
Ancient Egypt, Greece and Rome
Laxative / purgative – one of its oldest medicinal uses documented back to ancient Egypt and Greece/Rome. Also to help induce labor.
Medieval Europe
Inducing labor or easing childbirth
Ayurvedic and Unani Medicine
Topical use for skin and hair conditions and for colon cleansing in some traditional medicines. These traditional medicine systems have also used castor oil or leaf poultices for:
• Minor cuts
• Skin inflammation
• Ulcers
Africa
Used for skin infections, wound healing, and as a hair treatment.
Western Twentieth Century
In 1958, D. C. Jarvis, M.D. documented that he and associate physicians used castor oil externally for the following conditions:
• Warts: applied oil night and morning to ward, rubbing it lightly about 20 times.
• Skin ulcers: again, applied oil directly to ulcer
• Newborns: applied castor oil to the navels of newborns if they showed any slow healing
• Breast milk: applied to breasts to increase milk flow.
• Eye irritation: a drop of oil into the eye for irritation
• Child health: rubbed into scalp of growing child to stimulate health
• Eyelashes: applied to eyelashes to thicken and lengthen them
• Chest colds: applied to the chest with menthol
• Abrasions: applied to skin abrasions to decrease pain and speed healing
• Corns and calluses: applied directly onto the skin and rubbed in nightly
• Sore feet: massaged into the feed to relieve soreness.
• Papillomas: applied nightly
• Moles: rubbed into the mole nightly before going to bed
In the early twentieth century, Edgar Cayce greatly popularized the use of castor oil in the early to mid-twentieth century. His readings often prescribed castor oil pack applications.
William McGarey, M.D., worked many years with castor oil among many patients at his Phoenix medical clinic. He was also the medical director of the Edgar Cayce Medical Research Division, which documented the use of a number of Cayce’s prescriptions over the years.
Dr. McGarey, who emigrated from Yugoslavia to the United States in 1901, documented that castor oil was a standard treatment “back in the old country.”
The general Cayce prescription is for a castor bean oil pack. A pack is made by soaking two or three pieces of flannel cloth in the oil or applying a liberal amount onto the skin. Then the area is covered with a piece of felt cloth that has been soaked or covered with castor oil. The cloth is folded and applied to the skin. A barrier cloth or other material is then applied over the castor pack and wrapped around to prevent leakage.
Some of the ailments the pack was used for by Dr. McGarey and his associates included aphonie, appendicitis, arthritis, cancr, cholecystitis, cholecystalgia, colitis, constipation, epilepsy, gallstones, gastritis, migraine, hepatitis, hervia, Hodgkin’s disease, hookworm, cirrhosis, neuritis, multiple sclerosis, lymphitis, cerebral palsy, Parkinson’s, cellulitis, sterility, ringworm, uria and colic.
Many other traditional doctors have applied castor oil during their treatments. Dr. Jethro Kloss and Dr. Paavo Airola were advocates of the use of castor bean oil for cysts and warts.
In these treatments, castor oil was also applied as a massage oil or blended with other oils for a soothing and therapeutic massage.
Other plant part uses used traditionally
• Leaves: used traditionally for wound dressing, insect bite relief, stomachache, rheumatism.
• Roots / extracts: used in some cultures for jaundice, toothache, and liver ailments.
• Insect repellent and agricultural applications due to ricinine.
Health Benefits & Claimed Actions
Castor oil has been known for its various health benefits, which include:
Anti-inflammatory Properties
Castor oil is often used topically to reduce inflammation and relieve pain. It contains ricinoleic acid, which has been shown to have anti-inflammatory effects. Some research (see below) has indicated it can be useful for osteoarthritis.
Laxative Effect
It is a powerful laxative, commonly used to relieve occasional constipation. Ricinoleic acid triggers a strong laxative effect by stimulating the intestines.
Skin Health
Castor oil is frequently used in skincare products due to its ability to moisturize the skin, reduce acne, and promote wound healing.
Antimicrobial Properties
The oil possesses antimicrobial properties that help to combat fungal infections and bacteria.
Hair Health
It is believed to improve hair health by promoting hair growth, moisturizing the scalp, and preventing dandruff.
Accepted or Studied Effects
Stimulant laxative
Castor oil is approved by the U.S. FDA as a stimulant laxative for occasional constipation. The active component, ricinoleic acid, triggers intestinal smooth muscle contraction via prostaglandin receptors, increasing intestinal motility.
In animal and mechanistic studies, castor oil’s ricinoleic acid was shown to activate EP3 prostanoid receptors, explaining its laxative (and uterotonically stimulatory) effects.
Other Claimed Benefits (traditional / preliminary evidence)
- Antioxidant activities due to flavonoids and phenolics.
- Antimicrobial & antiviral potential (lab studies on leaf extracts).
- Anti-inflammatory, antinociceptive, antidiabetic effects suggested in some animal and in vitro studies.
- Moisturizing and skin barrier support when used topically.
Note that for many of these traditional uses, high-quality human clinical trials are scarce or lacking, and many claims rely on laboratory or animal research.
Skin Benefits of Castor Oil
Castor oil is chemically unusual among plant oils because it contains ~85–90% ricinoleic acid, a hydroxylated fatty acid. That hydroxyl group makes the oil:
• Thicker and more viscous than most oils
• Highly occlusive (reduces transepidermal water loss)
• Mildly anti-inflammatory in laboratory models
• Slightly antimicrobial in vitro
This chemistry explains most of its traditional and modern cosmetic uses.
Moisturizing & Barrier Support
Castor oil forms a semi-occlusive layer that slows water evaporation from the skin. While it is not a classic ceramide-replenishing oil, it can:
• Improve skin softness
• Reduce dryness and scaling
• Support healing of chapped skin
Dermatology
Castor oil is commonly used in dermatologic preparations and ointment bases because it enhances spreadability and moisture retention. It is frequently included in lip balms and healing salves.
Wound Healing Support
• Ricinoleic acid shows anti-inflammatory effects in lab studies.
• The oil environment supports moist wound healing.
• Some in vitro data suggest antimicrobial activity against certain bacteria.
Note that Castor oil is not a substitute for medical care in infected or serious wounds.
Anti-Inflammatory Properties
Animal studies have shown ricinoleic acid may reduce inflammation via prostaglandin modulation.
Potential applications (traditional or anecdotal):
• Eczema (mild cases)
• Dermatitis
• Psoriasis (as an emollient support, not treatment)
• Osteoarthritis (see study below)
Controlled human trials for inflammatory skin disease are very limited.
Acne Support (Use With Caution)
Castor oil has:
• Mild antimicrobial activity (in vitro)
• Anti-inflammatory properties
Acne downsides:
• It is thick and highly occlusive.
• It may clog pores in some individuals.
• It is considered low to moderate comedogenic risk depending on skin type.
Best suited for:
• Dry or mature skin
• Not typically ideal for oily/acne-prone skin unless diluted
Scar & Stretch Mark Use
Commonly used in:
• Scar massage
• Postpartum belly massage
• Stretch mark support
Scientific data specifically supporting scar remodeling are minimal, but improved hydration may enhance scar pliability.
Eyelash, Eyebrow & Hair Growth Claims
Castor oil is widely promoted for:
• Eyelash growth
• Eyebrow thickening
• Beard growth
However, there are no high-quality clinical trials proving it stimulates hair growth. Benefits may result from conditioning and reducing breakage rather than follicle stimulation.
Safety on Skin
Generally Safe When:
• Used topically
• Cold-pressed and properly processed
• Patch-tested first
Possible Side Effects:
• Contact dermatitis (rare but reported)
• Allergic reaction (more likely in individuals allergic to the plant)
• Eye irritation if misapplied
Avoid:
• Broken or infected wounds without medical guidance
• Heavy application on acne-prone skin
• In infants without medical supervision
What About Castor Oil Packs?
Castor oil packs (cloth soaked in oil applied to abdomen or joints) are widely used in naturopathic and traditional medicine for:
• Detoxification
• Lymphatic stimulation
• Liver support
• Joint inflammation
Scientific evidence for systemic detox effects is currently very limited. Most support is anecdotal or based on historical use.
Human Research on Castor Oil
In a 2009 study from India’s Postgraduate Institute of Medical Education Research, researchers tested 100 patients with knee osteoarthritis. They gave half the patients a castor oil capsule (9 mL) internally, three times a day for four weeks. The other 50 patients were given a diclofenac sodium capsule (50 mg - a conventional treatment for OA) three times a day for four weeks as well.
The researchers found both treatments were equally effective. However, the castor oil treatment group did not report any side effects, while the diclofenac-treated group adverse effects were significant according to the researchers.
In a 1994 study from Royal Children’s Hospital in Australia, researchers found that the lipase from castor oil could be beneficial for cystic fibrosis patients with pancreatic insufficiency.
Another study in 2012 found that Castor oil induces the relaxation and contraction of the uterus. This was thought to come from the ricinoleic acid activating properties. While focused on intestinal effects, this study helped clarify ricinoleic acid’s prostaglandin activity — relevant to inflammation modulation in tissues.
This laboratory study demonstrated the molecular mechanism of castor oil’s stimulant effects on intestine and uterus via EP3 receptor activation (animal & receptor studies supporting clinical actions).
A 2016 European Medicines Agency study evaluated castor oil in clinical use as a laxative. It reviewed studies showing its efficacy comparable to other laxatives and its historical medicinal use. This study concluded that short-term castor oil medicines have demonstrable laxative effectiveness, with safety and efficacy supported by long-standing usage data.
Risks and Precautions of Castor
• Toxicity of seeds: Ricin is highly lethal if seeds are ingested. Processing eliminates ricin in the oil, but seeds should never be eaten.
• Gastrointestinal side effects: oral use may cause nausea, abdominal cramping, diarrhea, electrolyte imbalance.
• Pregnancy caution: castor oil’s uterine stimulant potential means pregnant people should avoid self-administration for labor induction.
• Allergies: plant pollen and sap can provoke allergy/dermatitis.
Summary
Castor oil for skin is best understood as:
✔ A powerful occlusive moisturizer
✔ Mildly anti-inflammatory (based on mechanistic data)
✔ Supportive for dry, irritated skin
✔ Traditionally used for wound care and inflammatory conditions
Scientific References
Tunaru S, Althoff TF, Nüsing RM, Diener M, Offermanns S. Castor oil induces laxation and uterus contraction via ricinoleic acid activating prostaglandin EP3 receptors. Proc Natl Acad Sci U S A. 2012 Jun 5;109(23):9179-84. doi: 10.1073/pnas.1201627109.
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. doi: 10.1002/ptr.2804. PMID: 19288533.
EMA, Castor Oil – Well-Established Use and Laxative Efficacy Summary. EMA Herbal Summary Report, 2016. 2 February 2016 EMA/HMPC/572973/2014 Committee on Herbal Medicinal Products (HMPC)
Elkousy RH, Said ZNA, Abd El-Baseer MA, Abu El Wafa SA. Antiviral activity of castor oil plant (Ricinus communis) leaf extracts. J Ethnopharmacol. 2021 May 10;271:113878. doi: 10.1016/j.jep.2021.113878.
Ramothloa TP, Mkolo NM, Motshudi MC, Mphephu MM, Makhafola MA, Naidoo CM. Phytochemical Composition and Multifunctional Applications of Ricinus communis L.: Insights into Therapeutic, Pharmacological, and Industrial Potential. Molecules. 2025 Jul 31;30(15):3214. doi: 10.3390/molecules30153214. PMID: 40807390; PMCID: PMC12348877.
Abdul WM et al. Therapeutic role of Ricinus communis L. and its bioactive compounds in disease prevention and treatment. March 2018. Asian Pacific Journal of Tropical Medicine 11(3):177 DOI:10.4103/1995-7645.228431
Reilly HJ, Brod RH. The Edgar Cayce Handbook for Health Through Drugless Therapy. Virginia Beach: ARE Press, 1975.
Tursi JM, Phair PG, Barnes GL. Plant sources of acid stable lipases: potential therapy for cystic fibrosis. J Paediatr Child Health. 1994 Dec;30(6):539-43.
Airola P. How to Get Well. Phoenix: Health Plus, 1974.
Jarvis DC. Folk Medicine. Greenwich: Fawcett, 1958.