Castor oil has been used for generations across various cultures to help manage different health concerns. It is recognized in both traditional and modern medicine for its potential benefits.
However, castor oil may also cause certain side effects. The most commonly reported ones include skin rashes, diarrhea, nausea, and muscle cramps. Additionally, both internal and topical use of castor oil has been associated with other adverse effects in some individuals.
- What Is Castor Oil
- How Can Castor Oil Cause Side Effects
- What Are the Side Effects of Castor Oil
- Side Effects of Castor Oil Supplements
What Is Castor Oil
Castor oil is a pale yellow liquid extracted from the seeds of the castor plant (Ricinus communis). The method used to process the castor beans determines the type of oil produced, such as black castor oil or hydrogenated castor oil. The origins of castor oil use can be traced back to ancient Egypt, where its benefits were first recognized and applied.
Traditionally used in cooking and dietary practices, castor oil also plays a role in Ayurvedic medicine for managing various health concerns. It is known for its antimicrobial, anti-inflammatory, and strong laxative properties, which may help promote bowel movements, soften stools, and ease occasional constipation.
Due to its wide-ranging benefits, castor oil is a common ingredient in skincare, cosmetics, massage oils, and certain medicinal products. Its therapeutic strength largely comes from ricinoleic acid, which makes up about 90% of the oil and is considered its key active component.
How Can Castor Oil Cause Side Effects
Castor oil is classified by the Food and Drug Administration (FDA) as generally recognized as safe (GRAS) and effective when used as a laxative. Once ingested, it is processed in the small intestine where it releases an active compound known as ricinoleic acid.
Although ricinoleic acid was once suspected of being harmful to humans, studies under the National Toxicology Program found no toxic effects when castor oil was added up to 10% in the diet of rats. Limited human studies also supported these findings.
However, certain animal studies using undiluted castor oil reported adverse reactions. A review in the International Journal of Toxicology examined its impact on skin and showed varying levels of irritation. In some trials, undiluted castor oil caused severe redness in rabbit skin, while in others, it showed mild to no irritation in guinea pigs and miniature swine. While ricinoleic acid is not toxic on its own, it may increase the absorption of other substances through the skin, potentially leading to irritation.
Ingesting too much castor oil may cause more serious issues beyond skin irritation. Possible effects include chest pain, shortness of breath, muscle cramps, rectal bleeding, allergic skin reactions, and irregular heartbeat. It has also been associated with potential labor induction and rare reactions like acute hair felting.
What Are the Side Effects of Castor Oil
While castor oil offers a range of potential benefits, it may also cause side effects, especially when used in excess or without proper medical guidance. Below are some known side effects that have been observed in both clinical and anecdotal cases.
1. Nausea
Overconsumption of castor oil can lead to nausea. Although recovery is likely, untreated nausea can result in dehydration and electrolyte imbalance. Castor oil is sometimes used as preparation for radiological or colonoscopy exams, but many patients find its taste and texture unpleasant. According to an Iranian study involving 114 outpatients, about 28% of participants reported nausea along with vomiting, abdominal pain, fullness, and fainting.
2. Skin Rashes
Topical use of castor oil may cause mild skin irritation. Animal studies have shown that castor bean oil can irritate the skin, and in some cases, lead to redness or hives. While castor oil isn’t considered a major skin irritant in clinical tests, its main component, ricinoleic acid, may aggravate symptoms in people with existing skin conditions.
3. Muscle Cramps
Castor oil acts as a strong laxative, and excessive intake can lead to muscle weakness or cramps. It may also cause abdominal discomfort when consumed on an empty stomach. Ricinoleic acid interacts with smooth muscle tissue in the digestive system, sometimes resulting in intestinal contractions. Because of this, pregnant and menstruating individuals are generally advised to avoid it unless under medical supervision, as it may trigger uterine contractions and possibly early labor.
4. Dizziness
Dizziness may occur due to a castor oil overdose. Other symptoms can include fainting, shortness of breath, and in rare instances, hallucinations. Synthetic forms of castor oil are sometimes used alongside chemotherapy drugs, which can intensify adverse effects. If symptoms like dizziness, hives, fatigue, or irregular heartbeat arise, medical attention should be sought immediately.
5. Harmful for Newborns and Children
In some traditional practices, castor oil is given to infants soon after birth. This can lead to serious complications such as intestinal damage, diarrhea, pneumonia, or malnutrition. There is limited research on the safety of castor oil in newborns, lactating mothers, and children. Therefore, any form of castor oil—including supplements—should only be used under the guidance of a healthcare provider.
Always consult your doctor before using castor oil for medical or health-related purposes. Proper dosage and usage play a key role in minimizing risks.
Side Effects of Castor Oil Supplements
Castor oil supplements are typically available in soft gelatin capsule form and are often used to support hair health or manage skin conditions like dryness. While they may offer cosmetic benefits, excessive or improper use can lead to unwanted side effects.
Though there is limited scientific data on the safety or toxicity of castor oil supplements, anecdotal evidence raises concerns about potential contamination and the quality of ingredients. Some supplements may contain castor beans, which are highly toxic if not properly processed.
Excessive consumption of castor oil capsules may result in side effects similar to those of the oil itself, such as abdominal cramps, nausea, diarrhea, uterine contractions, allergic reactions, and abdominal pain.
Because their safety is not well-established, pregnant and lactating women are advised to avoid using castor oil supplements. Products that include additional ingredients like olive oil or other herbs may further increase the risk of allergic responses.
To minimize health risks, consult your healthcare provider before using castor oil supplements. A medical professional can recommend the correct dosage and determine whether they are safe for your specific health needs.