Castor Oil: Myths and Facts

As herbal products gain popularity both on store shelves and across social media feeds, you may have heard of castor oil’s purported benefits, ranging from enhanced vision to improved digestion.

Castor oil, made from the seeds of the castor plant, is an ingredient used in makeup, topical creams and skin care products and known for its moisturizing and anti-inflammatory properties. It’s also widely recognized as a natural laxative and as a stimulant for inducing labor.

While rooted in thousands of years of tradition as a natural treatment, the Food and Drug Administration has approved castor oil’s use only as a laxative.

“A lot of patients are looking for alternatives to prescription medications or over-the-counter remedies, and castor oil is an option [as a laxative],” says Ilana Kersch, clinical nutritionist in the Division of Digestive Diseases at NewYork-Presbyterian/Columbia University Irving Medical Center. “It’s not something that I’ve generally recommended, but I think it’s safe to try in small amounts. But there are reasons why you would want to be careful.”

Health Matters broke down the myths and facts with gastrointestinal dietitian Kersch, ophthalmologist Dr. Ashley Brissette, and OB/GYN Dr. Hoosna Haque. They explain what castor oil is used for, and its risks and benefits in their areas of expertise.

Amid increasing trends of people using castor oil to help with vision problems such as glaucoma, cataracts, or floaters, Dr. Brissette, an ophthalmologist at NewYork-Presbyterian/Weill Cornell Medical Center, says there is little scientific evidence behind its use in improving eyesight.

“One of the biggest complaints of dry eye disease is blurry vision that tends to fluctuate,” says Dr. Brissette, who is also an assistant professor of ophthalmology at Weill Cornell Medicine. “Castor oil is a moisturizing agent and people may notice a slight improvement because of that, but it doesn’t actually cure any of the conditions. If you do have an issue with your vision, meet with an ophthalmologist so they can determine how to treat it. Self-treating with castor oil is not the way to go.”

Using castor oil in your eyes can lead to infections, corneal ulcers, or even blindness, she adds.

“The danger is that it’s non-sterile and not formulated for the eyes, especially if you’re buying it from an unknown source and putting it directly into the eyeball,” Dr. Brissette says. “There are safer ways you can moisturize to help with vision that don’t carry the same risk as buying pure oil that hasn’t been tested to be pathogen-free.”

For dry eyes, moisturizing drops formulated specifically for the eyes can help alleviate symptoms. Daily washing over closed eyelids is also recommended to remove excess bacteria, pollution, allergens, and dust that can build up around eyelids and lashes.

Other home treatments for maintaining eye health include a warm compress over closed eyelids to soothe the eyes, as well as following a Mediterranean diet rich in omega-3s.

“There is good data around castor oil’s moisturizing properties, but we don’t have good evidence that it actually helps eyelashes grow,” says Dr. Brissette.

Castor oil can help coat and moisturize the lashes, giving them the appearance of looking thicker and shinier. Keeping lashes hydrated also keeps them healthy, which can promote natural growth.

“It’s found in a lot of cosmetics, lotions and soaps, which is why it’s probably safe to use around the eye, but not directly in it,” says Dr. Brissette.

Approved by the FDA as a laxative, castor oil can be used to alleviate occasional constipation.

The active ingredient in castor oil is ricinoleic acid, a type of fatty acid that stimulates the muscle contractions that move food through the digestive tract, explains Kersch.

To help with constipation, the recommended ingested amount ranges from 15 to 60 milliliters.

“Castor oil can be a more natural option if you’re allergic to any sort of additives or colorings found in other over-the-counter laxatives,” Kersch says.  “But I generally would not recommend using laxatives unless you really need to, like if you haven’t had a bowel movement in three or four days and need a one-time fix. It can be a little bit tougher on the gut, and as with any sort of laxative, you want to avoid overuse. If you overdo it, you can end up with a lot of discomfort, cramping, or diarrhea.”

Some studies show that castor oil can cause more side effects compared to other ingredients found in over-the-counter laxatives.

It’s also not recommended for people who may have a gastrointestinal blockage, appendicitis, or inflammatory bowel disease such as Crohn’s or ulcerative colitis, Kersch adds.

If used every day or multiple times a day, risks include loss of fluid through the stool, loss of electrolytes like sodium, potassium and magnesium, or weight loss.

While castor oil packs — a piece of cloth soaked in castor oil and applied to the skin — are gaining popularity as a treatment for cramps or digestive issues, castor oil needs to be ingested to be effective for gastrointestinal conditions, says Kersch.

“The heat from a castor oil pack could be soothing for gas or cramping, but it’s not going to be the same as if you drink it and stimulate the gut.”

For problems with constipation, making diet and lifestyle changes can help prevent you from getting to the point where you may need a laxative. Increasing the amount of water you drink, fiber intake, and exercise can help speed up digestion, and eating certain foods like flax and chia seeds, prunes, and kiwis help bulk up stool to help move them through your digestive system.

“Some people have the misconception that if it’s not a prescription it’s OK not to check in with a health provider. But it’s important to talk to a doctor or gastrointestinal dietitian since over-the-counter and natural remedies can have potential side effects,” says Kersch.

There are limited studies on the effects, but castor oil may help induce labor, says Dr. Haque, an OB/GYN at NewYork-Presbyterian/Columbia University Irving Medical Center who also specializes in integrative medicine. Some may view it as a more natural option for a healthy, uncomplicated pregnancy at or past their due date.

Its use has a long history dating back to ancient times. The same ricinoleic acid that helps move food through the digestive tract can stimulate uterine contractions during pregnancy. “With someone who is healthy and does not have any complications with their pregnancy, it’s thought to be safe, but maybe not that effective,” says Dr. Haque.

The typical dose is between 15 to 30 milliliters. Certain factors, such as a prior C-section need to be considered, and castor oil should be taken under the direction of a healthcare provider.

Dr. Haque, who is also an assistant professor of obstetrics and gynecology at Columbia University Vagelos College of Physicians and Surgeons, warns against trying to make castor oil yourself.

“The raw seed of the castor plant can potentially have some toxins, so you want to use a safe, well-purified product” she says.

Because of its laxative effects, using castor oil “could be a tough start to the labor process,” says Dr. Haque.

Castor oil may cause diarrhea, resulting in dehydration and possible electrolyte imbalances. Side effects also include nausea, dizziness, and cramping.

Makers of castor oil packs also claim that they can help with menstrual cramps, but there are few studies to support its benefits, says Dr. Haque.

The oil can be applied with heat to the stomach and lower back area, but the warming effect may have more impact than the castor oil itself. “Heat can improve the blood flow to and relax the uterus helping to relieve menstrual pain,” says Dr. Haque. “But, you also want to be aware that there may be more effective options if the cramps are significant and interfering with your normal activities.”