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Castor oil is a powerful natural laxative that people sometimes claim can aid in weight loss. But there is a lack of evidence that castor oil is effective for this goal.

Castor oil is a vegetable oil with a wide range of cosmetic and medicinal uses.

Some people swear by its weight loss effects, due to its laxative properties. Yet you may wonder whether any scientific evidence supports this claim.

This article examines whether using castor oil is a safe and effective weight loss approach.

What is castor oil?

Castor oil is a vegetable oil made from the seeds of the Ricinus communis plant, which is native to Eastern Africa but is now found worldwide (1).

Its seeds — commonly known as castor beans — contain ricin, one of the most potent and lethal substances known. However, castor oil itself does not contain ricin.

The oil has been widely used in traditional medicine to treat stomach disorders, arthritis, and insomnia, as well as menstrual cramps (2).

Today, it remains a popular treatment for constipation, hair growth, and skin dryness. It also has a variety of applications as a food additive and in the industrial industry as an ingredient in lubricants, paints, and biodiesel fuel (3, 4).

Weight loss

Castor oil has a long history of use in traditional medicine as a laxative.

It contains a compound called ricinoleic acid, which stimulates the intestinal muscles to contract. This can help push material through the bowels (5).

The Food and Drug Administration (FDA) categorizes castor oil as generally safe and effective to use as a stimulant laxative. However, its use for this purpose has declined over time, given the discoveries of more effective laxatives with fewer side effects (6, 7, 8).

Regardless, people have suggested that the laxative effect of castor oil can aid in weight loss.

While no studies have specifically examined the effects of castor oil on weight loss, the oil likely relieves constipation, which can result in weight loss (7, 9).

Keep in mind, though, that if you lose weight from relieving constipation, it may merely be the result of removing waste from your digestive system — waste that your body would already be getting rid of.

Aside from relieving constipation, no evidence suggests that castor oil has any direct or indirect ability to aid in weight loss, such as by increasing metabolism or decreasing hunger.

Other potential benefits

Despite the lack of evidence to support using castor oil for weight loss, some evidence supports its use for other benefits.

These include:

• Wound healing: Some test-tube and animal studies suggest that the oil may benefit wound healing due to its antibacterial effects (10, 11).
• Hair health: While the oil hasn’t been shown to improve hair growth or treat hair loss, one 2003 study found that it may increase hair luster (12).
• Pain relief: Animal studies, including an older one from 2000, have shown that the topical application of ricinoleic acid, which is found in castor oil, may reduce pain and swelling caused by inflammation (13, 14).
• Acne relief: Test-tube and animal studies have shown that ricinoleic acid inhibits the growth of certain bacteria that can cause acne (15).

Side effects

While castor oil is generally considered safe, it can cause negative side effects in some people.

• Induced labor: Ricinoleic acid, a compound found in castor oil, stimulates the same receptors in the uterus as it does in the intestines, so it increases contractions. For this reason, people who are pregnant should avoid consuming it (7, 16).
• Stomach discomfort: Castor oil can cause abdominal cramping, vomiting, bloating, and dizziness. Other laxatives may have fewer side effects (8).
• Disrupted electrolyte balance: As with the chronic use of any laxative, long-term use of castor oil can cause electrolyte imbalances and dehydration (7).
• Allergic reactions: While rare, the topical application of this oil may cause an allergic reaction in some people (6).

Health authorities have established an acceptable daily intake of up to 0.32 milligrams (mg) per pound (0.7 mg per kg) of body weight (17).

Other weight loss tips to try

There are no quick fixes for weight loss.

Safe, effective, and sustainable weight loss requires that you limit harmful habits and adopt healthier behaviors in their place.

Here are some healthy weight loss tips:

• Fill up on protein: Protein increases fullness, reduces muscle loss, and requires more calories to digest than carbs or fats (18).
• Eat more fiber: Eating more fiber-rich foods like fruits, vegetables, and whole grains can promote feelings of fullness and help you take in fewer calories throughout the day (19).
• Get active: Whether it’s walking, running, boxing, swimming, or weightlifting, find an activity you enjoy and try to do it regularly.
• Focus on sleep: Sleep is crucial for weight loss. Insufficient sleep increases hunger and makes it harder to lose weight (20).
• Self-monitor: People who engage in self-monitoring techniques, like regular self-weighing and tracking their diet and exercise, may be more likely to lose weight (21, 22, 23).

Making behavioral changes can be difficult, and it doesn’t happen overnight. Try to start by making small changes to your habits, and remember to be patient with yourself.

The bottom line

Aside from any weight loss that may result from relieving constipation, no evidence supports using castor oil for weight loss.

But the oil may have other uses and benefits related to wound healing, hair health, and the treatment of pain and acne.

If your goal is to lose weight, start by adding more fiber and protein to your diet, becoming more active, focusing on getting good sleep, and tracking your progress.

Well tested: Moringa and castor oils