Does Rosemary Oil Really Help Hair Growth?

 A woman applying rosemary oil to her scalp.
A woman applying rosemary oil to her scalp.

The sheer number of hair growth products out there—including hair growth oils, hair vitamins, and hair growth shampoos—attest to a tough truth: Hair loss ends up impacting just about everyone. Factors like diet, stress, genetics, and aging can all play a role in hair retention (or lack thereof), and every scalp is different. Usually, no single product promotes hair growth on every head, if it even works on some.

This hasn’t stopped people from swearing certain ingredients are lengthening, strengthening miracles, halting shedding and hair loss in their tracks. Most recently, scores of TikTok users have sworn by rosemary oil for hair growth. More than 31,000 HairTok posts are currently tagged with #rosemaryoilforhairgrowth, displaying before-and-after photos of thinning, receding hairlines dramatically transforming into thick, waist-length hair.

There’s some background to explain the excitement: The anti-inflammatory essential oil is said to stimulate circulation and promote nerve growth when applied directly to the scalp. But social media has a habit of exaggerating and spreading downright misinformation, even in beauty. There’s still one question to answer: Is rosemary oil for hair growth actually effective? Ahead, Anabel Kingsley, licensed trichologist and president of Philip Kingsley, breaks down for Marie Claire what the so-called miracle treatment can and can’t do for your hair.

Can Rosemary Oil Treat Hair Loss?

a woman applying oil to her scalp
a woman applying oil to her scalp

Rosemary oil's hair growth reputation includes a few claims. First, that it conditions and strengthens hair while also reducing breakage. Second, that it increases circulation in the scalp: accelerating hair growth by increasing blood flow to hair follicles.

So far, there isn't definitive evidence proving those benefits are legit. Rosemary oil's effects on hair haven't been rigorously tested in a clinical setting. One often-cited 2015 study comparing the effects of rosemary oil to minoxidil (the generic ingredient used in products like Rogaine) actually had too small a sample size to be definitive. And as Kingsley notes, that study was entirely made up of men.

That said, Kingsley concedes that rosemary oil is “unlikely to cause any harm” unless you develop contact dermatitis or have skin that can’t tolerate rich oils. If you have a greasy scalp or suffer from scalp acne, for example, hair oils of any kind might exacerbate the issue.

Should You Use Rosemary Oil?

a sprayer bottle with rosemary in it
a sprayer bottle with rosemary in it

The good news: There isn't proof that rosemary oil will harm your hair, unless you're already dealing with scalp irritation. The not-so-good news? There's also little proof that rosemary oil will be the deciding factor on your hair growth journey.

All those TikToks likely lack sufficient information about saturation or formula. Amounts can change from clinical study to final product—meaning that the former could have higher rosemary oil quantities (and potential efficacy) than the latter. "You might buy a serum with rosemary oil and maybe the clinical study on rosemary was done with 10 percent rosemary extract," Kingsley explains, "and your serum contains 0.2 percent.”

Claims that rosemary oil causes near-overnight hair growth are most likely false. In reality, Kingsley says hair loss treatments need more time for results to appear. “Any treatment for hair loss takes at least three months. For female pattern hair loss, I say give it about six months.”

Bottom line: Don't take social media's advice alone when searching for a hair growth remedy. “Watch it for fun if you want to, but get your advice from professionals,” Kingsley says. "Go see a specialist and get products that are clinically proven to work.”

Rosemary Oil Alternatives

someone holding rosemary branches in one hand
someone holding rosemary branches in one hand

Whether her patient is dealing with genetic hair loss, shedding, or aging, Kingsley prefers treatments that are proven to address the root cause. Female pattern hair loss can be treated with minoxidil, while shedding can be stopped by correcting vitamin and mineral deficiencies. As hair thins and sheds with aging, scientifically-backed treatments like adenosine or minoxidil are also Kingsley's preferred solution. "Often you can't completely regain the density that you lost," she says, "though you can improve it.”

Promises that you can transform your thin, sparse hair into a flowing, thick mane overnight are misleading at best—especially when those dubious results are attributed entirely to rosemary oil. Sometimes, your body's natural rhythms can clear up shedding on their own, making the best treatment nothing more than proper nutrition and stress reduction.

"A lot of the time, hair shedding is self-limiting, so it stops between three and six months after it started. It can be due to having Covid, high fever, stress, childbirth, or a period of a poor diet, which should then rectify itself if you start eating well again," Kingsley explains. "Your hair, in those instances, is just going to start growing back on its own anyway. Sometimes, using rosemary oil is just coinciding with your hair growth cycle recovering on its own.”

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