According to the Food and Drug Administration, castor oil is approved for just one medicinal use: as a laxative.
But scroll through social media and you’ll find various other health claims for the oil — which is pressed or extracted from castor beans. According to some, castor oil might ward off wrinkles, sharpen vision, induce labor, boost hair growth or even shrink tumors.
In July, Google searches for “castor oil” rose to their highest levels since 2004. But as interest in the oil soars, so do doctors’ concerns.
“I think sometimes people want to go viral, and so all these claims get made,” said Dr. Ashley Brissette, an ophthalmologist and spokeswoman for the American Academy of Ophthalmology. But castor oil, she stressed, is “not the cure-all that everybody makes it out to be.”
Here’s what castor oil can — and can’t — do.
Eye health
Popular posts on TikTok show people smearing castor oil over their eyelids in the hopes of sharpening their vision, reducing eye floaters or even improving cataracts or glaucoma. If the oil gets in your eyes? Even better, some say.
But no high-quality evidence suggests that castor oil can improve eye health, and especially not in terms of reversing cataracts or boosting vision, said Dr. Yvonne Ou, an ophthalmologist at U.C.S.F. Health.
Some eye drops do contain castor oil as a lubricant that can help with dry eyes, which in turn may reduce blurry vision, Dr. Brissette said. But those products are made with specific formulations tailored for use in the eye, rather than the pure castor oil people might order online, she added.
And if the oil is not sterile, getting it in your eyes can increase the risk of an infection, she said, which in turn can lead to a corneal ulcer (an open sore on the eye) or even blindness.
If you do end up getting castor oil in your eyes, and they become red or severely painful or your vision suddenly changes, seek out medical attention, she advised.
Tumors
Some on the internet say that castor oil can penetrate deep into the skin, and that placing an oil-soaked compress over the site of a cyst or a tumor (such as one caused by breast cancer) can break it up.
But Dr. Jun Mao, the chief of integrative medicine service at Memorial Sloan Kettering Cancer Center, said that he is unaware of any scientific evidence that backs those claims up.
Applying castor oil directly onto your skin probably won’t cause any issues aside from potential irritation, said Dr. Anna Shannahan, a family medicine doctor at Northwestern Medicine. But don’t assume that castor oil will fight cancer, she said.
“If that were the case, we’d probably be recommending it much more,” Dr. Shannahan said.
Labor
The decades-old claim that swallowing castor oil can induce labor in pregnant women does have some — albeit limited — evidence. In a small 2022 review of studies, for instance, researchers concluded that ingesting about four tablespoons of castor oil effectively led to a softening and opening of the cervix and induced labor.
But most of the buzz around castor oil and labor comes from anecdotal accounts, said Dr. Monica Woll Rosen, an OB-GYN at the University of Michigan Medical School. And while it’s possible that it could stimulate labor in some, it’s not something doctors recommend, she said — in part because drinking too much can cause extreme nausea, vomiting and diarrhea, which can result in dehydration.
That’s “the last thing we would want for a woman getting ready to start the labor process,” Dr. Shannahan said.
Constipation
The good news is that castor oil can be an effective laxative, though it can come with side effects like nausea and vomiting, Dr. Shannahan said. Castor oil is safe to consume in small quantities for constipation, depending on your physician’s recommendation, but it’s often not the preferred option when compared with other treatments for constipation.
Hair and lash growth
Many castor oil proponents say that rubbing it onto your eyelids or massaging it into your hair and scalp can lead to eyelash and hair growth — but yet again, no rigorous evidence supports this, said Dr. Angela Lamb, a dermatologist at Mount Sinai.
It’s possible that castor oil may add moisture to the hair, making it less prone to breakage and allowing it to grow longer, Dr. Lamb said, but it’s hard to say for sure without conclusive studies. “You don’t want to say that just because something hasn’t been studied and proven that it’s not helpful,” she said.
Skin health
Similarly, some people apply castor oil to the skin to prevent and reduce wrinkles and under-eye circles. While it can help moisturize your skin, there is no proof that it’s an effective anti-aging tool, said Dr. Shoshana Marmon, an assistant professor of dermatology at New York Medical College.
It also might have the unintended consequence of clogging your pores and exacerbating acne, she added.
It can be tricky to navigate the myriad health and beauty claims swirling around the internet, Dr. Marmon said. But “sometimes,” she said, “the science just isn’t there.”