Castor oil and rosemary oil for hair

So, you want longer hair and you've stumbled upon an internet hack that claims to help you do that. Yep, we're talking about castor oil for hair growth. Many have cited the ingredient as the reason for their longer, thicker hair, but with little science or proof to back the oil up. 

Before diving into these big claims, first things first: If you're struggling with hair loss or thinning, you're far from alone. It's extremely common, with American women accounting for 40 percent of Americans struggling with hair thinning or loss.

It tends to be most prevalent in your 40s and 50s, and this can occur for a laundry list of reasons, including hormonal changes, alopecia, and stress, so it's always best to visit your doctor to determine what's going on. Regardless of the reason, losing your hair can be extremely devastating for some — make that most — people, seeing as hair is an external factor that can greatly impact a person's self-image and confidence. (Thanks for that, societal pressure.)

It's for this reason that people can be quick to try any remedy that promises results. And we get it; those before-and-after photos will really get to you. The technology behind hair growth and hair loss treatments has improved in recent years, too, though it's worth noting that some of these treatments can be expensive and unsustainable. Because not everyone can afford to drop hundreds on an in-office treatment, many people turn to natural and DIY alternatives.

And that's where castor oil comes into play. Can it really help with growing out hair? To get a real definitive answer on this popular hair growth method, we turned to the experts. 

Meet the Experts

• Marisa Garshick, M.D., a board-certified dermatologist in New York City.
• Perry Romanowski, a cosmetic chemist and the author of Beginning Cosmetic Chemistry.
• Adam Friedman, M.D., a board-certified dermatologist and program director at The George Washington University School of Medicine & Health Sciences in Washington, D.C.

What is castor oil, and what are its benefits?

According to board-certified dermatologist Marisa Garshick, M.D., who is based in New York City, castor oil is derived from castor beans and is rich in protein, antioxidants, nutrients, and fatty acids. As a result, castor oil can possibly be helpful for skin, scalp, and hair. Dr. Garshick adds that some of its benefits include acting as a humectant to help draw moisture into the skin and that it has anti-inflammatory and antibacterial properties, which may help improve overall skin, scalp, and hair health.

Though it's often touted as an all-natural "panacea" (go ahead, Google it: you'll find article after article about how the viscous oil can help with a myriad of issues like shedding, breakage, and regrowth), that may not be the case. Unlike other popular oils and vitamins like rosemary oil and vitamin B5, both of which have studies that back up their aid in hair growth, Dr. Garshick says scientific evidence surrounding castor oil is lacking for both skin and hair.

Can castor oil help hair grow?

The tl;dr: no. "Castor oil will not grow hair," says Perry Romanowski, a cosmetic chemist and the author of Beginning Cosmetic Chemistry. "There is no evidence for it and no scientific theory supporting that it would work. So yes, it's a total myth."

Dr. Garshick agrees, and notes that all that's really known about castor oil for hair growth is that the ricinoleic acid found in it may boost circulation in the scalp and subsequently promote healthier and stronger hair — but this is all speculative at this point. "There is no conclusive evidence that castor oil can promote hair regrowth," she says. “However, anecdotally, people have noticed improvement." (Any testimonials about castor oil for hair growth are anecdotal, coming mostly from blogs, Reddit, and YouTube.) 

"While it does have antimicrobial properties that may be useful in terms of fighting off bacterial or fungal overgrowth on the scalp that can lead to hair-damaging inflammation, there is zero evidence [showing] it is helpful for hair growth," says Adam Friedman, M.D., a board-certified dermatologist and program director at The George Washington University School of Medicine & Health Sciences. 

He adds that some people can actually be allergic to castor oil and experience inflammation, ultimately doing more damage than good to the scalp. "To propose that castor oil accelerates hair growth, a tightly regulated process (one centimeter per month) for which FDA-approved medications for hair loss do not impact, is ridiculous," he states.

In better news, Romanowski says that castor oil is not damaging to the hair and can provide some conditioning that improves the flexibility of the hair fiber. Dr. Garshick also echoes this statement: "It can work to nourish the hair, leaving the hair feeling and looking stronger and healthier," she says. "Since it may have other benefits for the hair and scalp, it [may] promote a healthy environment for hair regrowth."

That being said, if you still want to try castor oil for hair growth despite it not having any real scientific proof, you can totally do so — regardless of hair type. Dr. Garshick says you can massage a small amount of castor oil directly onto the scalp and leave it on for about 15 to 20 minutes before rinsing out your shampoo. 

She adds that you can find castor oil in some of the best hair oils (her personal picks are Briogeo B. Well Organic + Cold-Pressed 100% Castor Oil and Nioxin Night Density Rescue Treatment) and you can just use as directed. 

Briogeo B. Well Organic Cold-Pressed 100 Castor Oil

$26 at Allure Shop

Nioxin Night Density Rescue Treatment To Promote Hair Thickness

$45

What can you actually do to help hair grow?

Even if castor oil isn't clinically proven to help you grow your hair, there are plenty of other things you can do to help the process along. Dr. Garshick lists taking vitamins like iron and vitamin D to promote hair growth. She adds that using anti-fungal shampoos can help, as well as in-office procedures using platelet-rich plasma that can be used to help promote hair growth and improve hair density.

But the best way to help hair growth is to prevent it from getting it to a point where it's thinning out. "Just as important as helping hair to grow is preventing further loss by minimizing trauma to the hair and avoiding tight hairstyles which can put tension on the hairs," she says. "If you are experiencing hair loss, it is always best to speak with a board-certified dermatologist to determine the best treatment options."

Well, there you have it. Without legitimate clinical evidence, there's no way of telling whether castor oil is the hair-care cure-all some people claim it is. That being said, as long as you consult your doctor first, there should be no problem with you experimenting with it on your own to see how and if it works for you. So until there's more science-backed information on the subject, it's best to take any glowing testimonials with a grain of salt.

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