Rosemary Oil for Hair Growth: Does It Really Work?

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 can impact just about everyone. Factors like diet, stress, genetics, and aging all play roles 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 has long been said to stimulate circulation and promote nerve growth when applied directly to the scalp. Board-certified dermatologist Dr. Naana Boakye notes that rosemary oil has been a mainstay home remedy for hair loss for years and that scientists have been taking a serious look at its potential since 2010. It's only blown up in popularity recently because of viral moments online, including the runaway popularity of Mielle Organics' hair growth products, which heavily incorporate rosemary oil and are rooted in its founder's personal journey with hair loss.

However, social media has a habit of exaggerating, even within the world of beauty. This begs the question: Is rosemary oil for hair growth actually effective? Ahead, Dr. Boakye and Anabel Kingsley, licensed trichologist and president of Philip Kingsley Trichological Clinic, break down what the purported miracle treatment can and can’t do for your hair.

Can Rosemary Oil Treat Hair Loss?

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.

One oft-cited 2015 study comparing the effects of rosemary oil to minoxidil (the generic ingredient used in products like Rogaine) showed that rosemary oil mitigates the effects of androgenetic alopecia because it assists with microcapillary perfusion (AKA circulation to tissue beds like the scalp). Plus, Dr. Boakye says, "Rosemary oil has anti-inflammatory, antimicrobial, and antioxidant properties which can relieve scalp irritation, reduce dandruff, and aid in promoting hair growth."

However, a single study doesn't meet the standard of rigorous testing. Plus, Kingsley points out that this study had too small a sample size to be definitive and that its subjects were all men. Plus, while rosemary oil has properties that support a healthy scalp environment, Dr. Boakye points out, "There is limited evidence to support that rosemary oil actually causes regrowth." She adds that some users can see an increase in hair thickness after regularly applying rosemary oil with a scalp massager (or by massaging the area with your fingers) because the practice stimulates and enlarges the follicles themselves. However, this stimulation can be attributed more to the massage than to the rosemary oil itself. To promote hair growth, opt for a scalp serum that nourishes your follicles.

Should You Use Rosemary Oil?

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.

Concentration matters, too. All those TikToks likely lack sufficient information about saturation or formula, and 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.” 

Making an oil that's too concentrated can backfire, too. Dr. Boakye warns, "Rosemary oil is highly concentrated and if it is not diluted with a carrier oil, it could cause scalp irritation, which could result in hair loss. Additionally, I advise those who are pregnant or breastfeeding against using rosemary oil and recommend those with medical conditions to consult a doctor before using it."

Futhermore, claims that rosemary oil causes near-overnight hair growth are false, because, as Kingsley points out all hair loss treatments need more time for results to appear. “Any treatment for hair loss takes at least three months," she says. "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

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.”

The Best Rosemary-Based Hair Products

Meet the Expert

Anabel Kingsley

Anabel Kingsley is a trichologist and president of Philip Kingsley Trichological Clinic in New York City.