A trichologist weighs in.
Our editors handpick the products that we feature. We may earn commission from the links on this page.
Longing for longer, healthier locks? Hair growth is a surprisingly common concern, and there are all kinds of products out there—from vitamins, to serums, to oils—that promise to deliver those Rapunzel-like strands.
One of the most commonly touted today is castor oil. This inexpensive and widely-available oil is a type of vegetable oil that's derived from castor beans, says Audrey Kunin, a board-certified dermatologist. "It is rich in ricinolenic acid, which is a nourishing, hydrating fatty acid."
And though it's surging in popularity, particularly for applications like hair growth, it's an oil that's been used for millennia for numerous topical and beauty applications, says William Gaunitz, FWTS, certified trichologist and founder of Advanced Trichology.
But is it worth picking up a bottle and applying regularly? Does it actually help stimulate hair follicles to deliver the real, tangible results you're looking for?
Does castor oil increase hair growth?
The short—and, admittedly, rather unsatisfying—answer? Maybe.
There is no evidence that castor oil applied to the scalp or hair will directly help increase hair growth, says Kunin. Rather, castor oil can indirectly assist in hair growth, says Gaunitz.
"It has many anti-inflammatory properties including high levels of omega 6 and 9s and vitamin E," he explains. Because of this, regular use—particularly alongside other proven products available through a dermatologist or trichologist can yield positive hair growth results, says Gaunitz.
But it shouldn't be relied on in every case. While castor oil can be very helpful in assisting in hair regrowth for people dealing with inflammatory hair loss, it will have very little to no impact on severe male or female pattern hair loss and nutritional hair loss, he explains.
How often should you apply castor oil?
If you fall into the former category or simply want to use the oil to reap the benefits of improved scalp health and silkier, healthier-looking hair, apply the oil two to three times per week, says Gaunitz. In some severe cases, you can use castor oil daily, but should mix with 50 percent coconut oil, since the product can create sticky buildup, he adds.
It's an easy process: Simply place a couple of drops into your hand and gently massage the oil into the scalp. Let the oil sit for 45 minutes to an hour. Then, wash your hair and scalp with your preferred shampoo and conditioner.
Can you leave castor oil in your hair overnight?
Maximum benefits, please! While you can technically leave castor oil in your hair overnight, leaving any oil on overnight or for longer than four hours should only be done intermittently, says Gaunitz. "After four to six hours the oil will break down and begin to collect dead skin cells and debris leading to possible inflammation."
How long does it take castor oil to work?
Within 15 to 30 minutes of use, castor oil begins to reduce inflammation and out-of-balance microbials including fungus and bacteria, plus deliver hydrating omega fats, says Gaunitz.
When it comes to hair growth, though, you'll have to dig deep for a little more patience. "For people who will benefit, I have seen positive results typically after six to eight weeks of use," he says.
Still, it's important to note that results won't last forever. Ongoing use is required to maintain the benefits of castor oil, Gaunitz adds.
The Best Castor Oil for Hair Growth
This castor-oil is cold-pressed for maximum benefits. And in addition to the dropper, it also comes with a spoolie, so you can use the oil on your lashes, too.
Briogeo Organic + Cold-Pressed 100% Castor Oil
From one of the most beloved brands in haircare comes a wholly organic and cold-pressed castor oil to promote hair, scalp, skin, and brow health.
Kreyòl Essence Haitian Black Castor Oil
Black castor oil is known to be particularly rich in all of the necessary vitamins and minerals to promote hair growth, including omega fatty acids and vitamin E.
Brigitt Earley
Contributing Writer
Brigitt is a writer, editor and craft stylist with nearly 15 years of experience. She specializes in lifestyle topics, including home, health, parenting, beauty, style, food, entertaining, travel and weddings. She has written for Glamour, People, Good Housekeeping, Women's Health, Real Simple, Martha Stewart, Apartment Therapy, The Spruce, and more.
Watch Next
Advertisem*nt - Continue Reading Below
Hair
Advertisem*nt - Continue Reading Below
Advertisem*nt - Continue Reading Below
