The kitchen herb that took over hair TikTok. What the one famous trial really found, why it matters that it used 2% minoxidil, how to use the oil without irritating your scalp, and what 12 skincare experts said about it on camera.
Rosemary oil is all over your feed, usually with the promise that it grows hair as well as minoxidil. It is cheap and it is natural, so what is the catch? Does it actually work? How long do you have to use it? And can you just put it straight on your scalp?
So what do the experts actually say? They are split, and most of the argument comes back to one small trial from 2015. The fans see a cheap, gentle option worth a try. The sceptics point out that it was only compared with the weaker 2% minoxidil, and that there is very little else to go on.
That split is why rosemary oil's Guru Score is 42%. The low score reflects doubt: many of the experts are unconvinced it does much, and several would keep minoxidil as the main treatment. Below, what the experts said sits next to what that trial and the other studies actually show, so you can see where the two line up.
Rosemary oil is a plant essential oil that people massage into the scalp in the hope of slowing hair loss and regrowing hair. The experts we track are split, and many are unconvinced. The main evidence is one trial in 100 men with pattern hair loss: after six months, rosemary oil and 2% minoxidil had raised hair counts by a similar amount, and neither group had changed at three months [1, 2]. But 2% is the weaker strength of minoxidil, and 5% regrew 45% more hair than 2% in a separate trial [3]. Like other essential oils, it can cause allergic reactions on the skin [7, 8], so it should never go on neat.
| Question | What we found |
|---|---|
| What is it used for? | Thinning hair and pattern hair loss, mostly on the strength of one trial [1]. |
| Do skincare experts recommend it? | Many are unconvinced. The fans see a cheap, gentle option, and the sceptics see one weak comparison. |
| Is it as good as minoxidil? | It matched 2% minoxidil in one trial [1]. That is the weaker strength; 5% does better [3]. |
| How long until it works? | In the trial, neither group improved at three months; both did by six months [1]. |
| Can it irritate? | Yes. Scalp itching rose in both trial groups [1], and rosemary can cause allergic contact dermatitis [8, 9]. |
| Rosemary water? | We found no human trial of rosemary water for hair loss. The trial tested the oil [1]. |
Rosemary oil is the essential oil of the rosemary plant, Rosmarinus officinalis, the same herb you cook with [2]. It carries compounds such as rosmarinic acid, 12-methoxycarnosic acid and camphor, which have antioxidant and anti-inflammatory activity in lab studies [2].
The experts who like it give three reasons it might help hair. Dr. Shereene Idriss, a dermatologist, says it improves blood flow, blocks DHT (the hormone behind pattern hair loss) and calms inflammation. Dr. Somji Skin, a cosmetic surgeon, says it has been proven to block DHT. The DHT evidence is thinner than that sounds: it comes from test tube and mouse experiments with a rosemary leaf extract, not from people using the oil [4]. Lab Muffin Beauty Science, a cosmetic chemist, points out that this kind of leaf extract is chemically quite different from the essential oil sold for your scalp.
Here is what each of them said on camera, with a link to the moment they said it.
rosemary oil is as useless as 2% minoxidil and can burn your scalp. There's no standard preparation for rosemary oil or rosemary water for that matter for hair growth.Watch ▸
In my opinion, no, for me the lack of clinical trials besides this one puts it back at the bottom of the heap. There isn't much to support it apart from mechanistic reasons which just don't really give it a great chance of working, and the level of this mechanistic evidence is really not that high either.Watch ▸
But if you're not able to tolerate even the foam, then maybe you can consider rosemary oil. But I'm still not convinced that it does a good job at regrowing hair, especially for those with androgenetic alopecia.Watch ▸
Rosemary oil is thought to work by improving the scalp circulation and reducing inflammation around your hair follicles. But it's not a miracle overnight fix. You need consistent use. [...] At least 6 months [...] to really [...] start seeing results. The study was small, and another really big issue is that it was comparing it to 2% minoxidil. [...] Most derms recommend 5% minoxidil. I have a feeling that the 5% minoxidil would outperform rosemary oil.Watch ▸
Rosemary oil is a nice adjunct to use. It has been shown to be as effective as minoxidil, however you have to use it twice a day, not just once a day, for at least six months to see full effect. [...] It helps to improve blood circulation, block DHT, it is an anti-inflammatory and has great antioxidant properties.Watch ▸
So yes, I'll accept your Rosemary Oil. I have nothing to raise you. You definitely don't want to use 100% pure Rosemary Oil because it is an essential oil that can irritate the scalp. [...] Don't ditch your minoxidil for the Rosemary Oil. In fact, just use them together because they could have potential benefits together.Watch ▸
The experts are split, so the caveats are where the useful detail sits.
Nearly the whole case rests on one trial. A 2024 review of natural treatments for pattern hair loss lists it as the one human study behind rosemary oil, alongside a study in mice, and says further studies are needed [2].
Researchers randomly gave 100 people with pattern hair loss either rosemary oil or 2% minoxidil for six months [1]. A later review describes the trial as single-blind and the patients as men aged 18 to 49 [2]. At three months, hair counts had not changed in either group. At six months, both groups had more hair than at the start, and there was no significant difference between them [1].
On side effects, scalp itching went up from the start in both groups, and it was more common with minoxidil at three and six months [1]. Dry hair, greasy hair and dandruff did not change significantly in either group [1]. So rosemary oil itched less than minoxidil, but it did not leave the scalp untouched.
The trial had no placebo group, so it cannot say how much of the gain either treatment caused [1]. And its yardstick was 2% minoxidil. In a 48 week trial in 393 men, 5% minoxidil regrew 45% more hair than 2% [3]. Dr. Mamina and Dr. Jenny Liu, both dermatologists, make exactly this point, and Dr Dray calls 2% minoxidil suboptimal. Matching the weaker strength is not the same as matching the treatment dermatologists actually recommend. The published summary also does not say what strength of rosemary oil was used [1].
A 1998 trial in 86 people with alopecia areata, a different, autoimmune kind of hair loss, found that massaging in a blend of thyme, rosemary, lavender and cedarwood oils helped 44% of people, against 15% on carrier oils alone [5]. It is a real result, but rosemary was one of four oils, and alopecia areata is not pattern hair loss. The DHT studies were done in mice and test tubes [4].
Dr Dray suspects that much of the benefit people report comes from rubbing the oil in. There is a little evidence for massage on its own: in nine men who used a scalp massage device for four minutes a day for 24 weeks, hair got thicker [6]. It was a tiny study with no comparison group, so it is a possibility, not a verdict.
Minoxidil has far more evidence behind it. The NHS names minoxidil and finasteride as the main treatments for hereditary hair loss, though neither works for everyone and both only work while you use them [11]. 5% minoxidil beats 2% in men [3], and rosemary oil has only been compared with 2% [1]. Our minoxidil guide has the detail.
The experts who see a place for it mostly see it as a fallback. Dr. Daniel Sugai, a dermatologist, would only consider it for someone who cannot tolerate even minoxidil foam, and he is still not convinced it regrows hair. Dr. Somji Skin says he uses it during breaks from minoxidil or when minoxidil irritates his scalp, and then goes back to minoxidil. Doctorly, a channel run by two dermatologists, says not to ditch minoxidil for it.
Hair loss has many causes, and the right treatment depends on which one you have. The NHS says to see a GP to find out what is causing your hair loss [11]. Dr Dray warns that trying home remedies first can mean losing time on a type of hair loss that needs proper treatment.
The 2015 trial tested rosemary oil [1]. We found no human trial of rosemary water for hair loss, and none of a rosemary shampoo. Dr Dray notes there is no standard preparation for either the oil or the water for hair growth. Doctor Youn, a plastic surgeon, uses a rosemary oil shampoo and cites the trial, and Dr. Somji Skin suggests a shampoo as an easy way to start, but a product that rinses off is not what the trial studied.
If you want to try it, the experts' advice is consistent: dilute it, be patient, and stop if your scalp complains.
Doctorly warns against using 100% rosemary oil because it can irritate the scalp. Dr. Mamina mixes a few drops into a carrier oil such as jojoba or coconut oil and massages it in. That fits the wider evidence: across essential oils, most allergic skin reactions come from pure oils or high-concentration products [7].
Rosemary is a known, if uncommon, cause of allergic contact dermatitis: there are case reports from rosemary alcohol rubbed on the skin, from a cleansing gel with rosemary leaf extract and from carnosol, one of rosemary's own compounds [8, 9, 10]. People who react to rosemary may also react to related plants in the mint family [8]. Dr Dray says rosemary oil can burn the scalp. If your scalp becomes red, itchy, sore or flaky, stop and see a doctor if it does not settle.
In the trial, neither treatment had changed hair counts at three months; the gains showed at six [1]. Dr. Mamina and Dr. Shereene Idriss both say to allow at least six months of consistent use.
Dr. Sam Ellis, a dermatologist, points out that many people start rosemary oil after a big shed caused by childbirth, illness or stress, and then credit the oil when their hair grows back on its own. That pattern is real: this kind of shedding, called telogen effluvium, starts two to four months after the trigger and usually corrects itself once the trigger is gone [12].
We found no studies of rosemary oil on the scalp in pregnancy or breastfeeding, so the research is limited. Dr. Daniel Sugai suggests running any rosemary oil product past your obstetrician first. Ask your doctor or midwife before you start.
Most of the experts treat rosemary oil as an extra rather than a whole plan.
The experts disagree here. Doctorly suggests using the two together, while Dr. Somji Skin warns that mixing them could be a recipe for disaster because nothing has tested the combination. We found no trial of the two used together either. If you want to try both, ask your doctor first, and keep minoxidil as the treatment you rely on.
Massage is part of how most people use the oil anyway, and it may be doing some of the work [6]. Dr Dray suggests the massage itself is the likelier benefit.
Dr. Sam Ellis puts rosemary oil in the same bracket as castor oil and rice water: strong anecdotes, little science. Our castor oil guide covers that one. Mad About Skin, a skincare creator, says he got better results from copper peptides than from the rosemary oil he used before, and moved away from rosemary partly because it left a film on his hair.
Possibly a little, but the evidence is thin. In one trial in 100 men with pattern hair loss, rosemary oil raised hair counts after six months by a similar amount to 2% minoxidil [1, 2]. There was no placebo group, and we found no other human trial for pattern hair loss. The experts we track are split, and the sceptics say one study is not enough.
As good as 2% minoxidil in one trial, and that is the weaker strength [1]. In a separate trial in 393 men, 5% minoxidil regrew 45% more hair than 2% [3], and we found no trial comparing rosemary oil with 5%. Dr. Mamina, a dermatologist, expects 5% would outperform it.
Around six months, if it works for you. In the 2015 trial, hair counts had not changed in either group at three months and had risen in both by six months [1]. Dr. Mamina and Dr. Shereene Idriss both say to give it at least six months of consistent use before judging it.
Yes. Doctorly, a channel run by two dermatologists, warns that pure rosemary oil can irritate the scalp, and Dr. Mamina mixes a few drops into a carrier oil such as jojoba or coconut oil. Across essential oils, most allergic skin reactions come from pure oils or high-concentration products [7].
It can. In the trial, scalp itching rose in the rosemary oil group as well as the minoxidil group, though less often with rosemary [1]. Rosemary can also cause allergic contact dermatitis, and people who react to it may react to related plants in the mint family [8, 9]. Stop if your scalp turns red, itchy or sore.
There is no evidence to choose between them. The one trial for pattern hair loss tested rosemary oil [1], and we found no human trial of rosemary water for hair loss. Dr Dray, a dermatologist, points out that there is no standard way to make either one for hair growth, so homemade versions vary.
The experts disagree, and the pairing is untested. Doctorly suggests using them together and not dropping minoxidil, while Dr. Somji Skin, a cosmetic surgeon, warns that combining them untested could go badly. We found no trial of the two together. Keep minoxidil as your main treatment and ask your doctor before adding anything to it.
Not in any study in people. A rosemary leaf extract blocked the enzyme that makes DHT in test tubes and helped hair regrow in mice [4]. That was an extract, not the essential oil sold for scalps, and mice are not people. Dr. Shereene Idriss and Dr. Somji Skin mention the DHT effect, but it has not been shown on a human scalp.
There is one encouraging trial, but not for rosemary alone. In 86 people with alopecia areata, massaging in a blend of thyme, rosemary, lavender and cedarwood oils helped 44%, against 15% on carrier oils alone [5]. Alopecia areata is an autoimmune condition that needs a doctor, so see one rather than relying on oils.
We found no trial of a rosemary shampoo for hair loss. The 2015 trial tested rosemary oil, not a product that rinses off [1]. Doctor Youn, a plastic surgeon, uses one, and Dr. Somji Skin suggests a shampoo as an easy starting point, but that is their preference rather than tested evidence.
Some of it may be natural regrowth. Dr. Sam Ellis, a dermatologist, notes many people start it after a big shed, and that kind of shedding (telogen effluvium) usually corrects itself once the trigger passes [12]. Dr Dray suspects the scalp massage does some of the work, and a tiny study found massage alone thickened hair [6].
The research is limited. We found no studies of rosemary oil on the scalp in pregnancy or while breastfeeding. Dr. Daniel Sugai, a dermatologist, suggests checking any rosemary oil product with your obstetrician first. Ask your doctor or midwife before you start, and do not use it neat.
12 experts, 20 mentions, every one traced to a video you can watch. Sponsored takes are excluded.
This guide combines two kinds of information. The expert consensus comes from 20 mentions of rosemary oil by 12 skincare experts in their YouTube videos. Each one was read, given a Yay, Mixed or Nay verdict and linked to the moment it was said. Sponsored takes are excluded. The research sections summarise published studies and medical sources, listed in full above.
The Guru Score measures how warmly the experts talk about rosemary oil. It is not a measure of clinical effectiveness, and this guide is not medical advice. If you are losing hair, see a doctor to find out why before you treat it. It has not been reviewed by a doctor.
This guide is general information, not medical advice. The Guru Score reflects how warmly the experts we track talk about rosemary oil; it is not a measure of clinical efficacy. Speak to a dermatologist or doctor about a diagnosed skin condition, and before using any medicine.
Dr. Jenny Liu
Dr. Sam Ellis
Dr. Somji Skin
Mad About Skin