Can Castor Oil Treat Breast Cancer?

People claim that castor oil can do everything from “detox” your liver and reverse wrinkles to regrow your hair. Scroll through the more than 300,000 TikToks with the hashtag #castoroil and you’ll see videos of people rubbing it on their eyelashes and neck, or placing castor-oil soaked patches (called “castor oil packs”) over their belly buttons. Eventually you might start to wonder, what can’t castor oil do? 

But as with many health trends that take off on social media, the hype outpaces the science. Many of the claims are unproven, and some are just plain false. One widespread and potentially harmful claim is that castor oil can treat breast cancer. It can’t. Here’s what the science says about castor oil and many of its supposed health benefits.

Castor oil is a vegetable oil made from the seeds of the Ricinus communis L. plant. Castor oil likely originated in Asia and Africa and has been used for medicinal purposes for thousands of years. Today it’s used to make a number of products including lubricants, cosmetics, and soaps.

When it comes to health, castor oil has a more limited role than social media might lead you to believe. Its only FDA-approved use is as a stimulative laxative, meaning it triggers the bowels to move stool along the intestines. 

Researchers have studied other potential medical uses of castor oil because it has shown some antioxidant and anti-inflammatory properties. But much of this research is in mice. There are no human studies that prove its effectiveness for anything other than as a laxative, says Lisa Larkin, MD, an internal medicine physician, specialist in menopause care for people with a history of breast cancer, and founder of HERmedicine. 

There’s no research that supports applying castor oil to the breasts to shrink tumors, break up cancer cells, prevent or lower the risk of breast cancer, or treat the disease. Social media videos claiming that breast cancer can be massaged away with castor oil are false.

The myth that castor oil can treat breast cancer may have roots in ancient Greece, where castor oil was used as a breast cancer treatment. 

A topical oil cannot penetrate breast tissue, locate a tumor, or destroy cancer cells. Even though castor oil and some of its compounds are being studied for their potential health properties, this is under lab conditions, which is a long way from treating cancer in humans. 

These social videos are tempting because they show a simple, inexpensive solution, but using castor oil in place of real medical care can be a dangerous move, says Larkin. “Data suggest that people who use complementary and alternative treatments … often avoid evidence-based treatment,” like surgery, radiation, and drug therapies, she says. 

A note about animal and cell studies

Studies in cells and animals are called preclinical studies because they’re done before any studies involving people. They are critical to developing new treatments for breast cancer. But just because a treatment works in a test tube or a mouse doesn't mean it will work in people. When a treatment enters a human body, it interacts with various systems, including the immune system. Experiments on cancer cells in a dish or a mouse can’t replicate those human conditions. This is why early results from preclinical studies can be promising and exciting, but don’t always lead to new treatments for people.

A few studies have looked into castor oil’s potential use for everything from wound healing and anxiety to hair growth. Here’s what the research says about some of the other common claims about castor oil.

Constipation

Castor oil’s active ingredient is ricinoleic acid, a type of fatty acid that stimulates the muscle contractions that move food through the digestive tract. Though castor oil is approved as a laxative, it’s not recommended as a first-line treatment for constipation. It may cause more side effects than other over-the-counter laxatives. Experts also caution that it shouldn’t be used by people with inflammatory bowel disease (IBD) because it can worsen symptoms.

Eye problems

There’s a growing trend of people putting castor oil directly into their eyes in the hopes of improving their eyesight, treating glaucoma and floaters, and helping with other vision problems. Not only is there no evidence that castor oil helps with any eye or vision problems, it can cause eye irritation, cornea damage, and raise the risk of eye infection. 

Hair growth

A 2022 study published in the Journal of Drug in Dermatology looked at whether castor, coconut, and argan oils improved hair growth and quality. Study authors found that there is no strong evidence to support the use of castor oil for hair growth and only weak evidence to support its use for improving hair quality. 

Anxiety

Early results from one 2024 study in mice suggest that castor oil and ricinoleic acid reduced anxiety-like behaviors in mice. More research is needed to understand how castor oil might affect anxiety symptoms in people.

Inducing labor

A 2022 review of a dozen studies found that castor oil can be effective in bringing on labor in full-term pregnant women. Castor oil also increased the chances of a vaginal delivery and no serious complications were reported. More research is needed to confirm that castor oil is effective for inducing labor and safe for pregnant women and babies. 

Because castor oil can cause contractions and early labor, pregnant women should not take it.

Wound care

Castor oil is sometimes used in wound care because it may help the healing process. For example, castor oil is hydrating and helps the skin maintain moisture while allowing oxygen to reach it, two things that can support the growth of new skin.

In one case study, castor oil was used successfully in a woman with breast cancer who developed a severe side effect of radiation therapy. The reaction, called wet desquamation, causes the outer layer of skin to peel off. Castor oil completely healed her skin in 14 days. 

While castor oil shows promise in healing skin, you should always talk to your surgical team before applying it to yours. 

Massage and using occlusive and emollient moisturizers (products that work together to soften skin and keep it hydrated) may help soften scars, says Larkin. And there’s no data to suggest castor oil works better, she says. 

Castor oil packs

Some people make castor oil packs by soaking cloth in castor oil and putting it on their skin. People on social media claim applying these castor oil packs to your body can help ease inflammation; “detox” the body; and relieve pain from arthritis, cramps, and endometriosis. But there’s no scientific evidence to support these claims. One small study on castor oil packs found that not enough is absorbed through the skin to have any effect. Additionally, castor oil packs may lead to rash or other skin reactions.

Common side effects of castor oil include stomach cramping and feelings of fullness, nausea, vomiting, fainting, and trouble sleeping. It can worsen symptoms of IBD, and may start early labor in pregnant women. Castor oil can cause irritation, infection, or other damage when put in your eyes, and irritation and skin changes when applied to your body.

Though castor oil is a legitimate laxative and can help hydrate skin, it might not be the best or most effective option. Most of castor oil’s other uses are unproven or false. 

Talk to your medical team before trying castor oil or any other alternative treatment because the risks might not outweigh the benefits. 

And be wary of social media claims, says Larkin. “Castor oil should not be a substitute for other therapies.”