Rosemary oil for hair growth: what the evidence really says
Quick answer: There is some early evidence for rosemary oil and hair growth, but it is thin. The study everyone quotes had 100 people, lasted six months and found rosemary oil did about as well as 2% minoxidil. That is one small trial, not proof. If you try it, dilute it, test a small patch of skin first, and get your hair loss checked if it is sudden, patchy or getting worse.
If you have seen rosemary oil all over TikTok and want a straight answer on whether it is worth your money, this post is for you. We look at what the research actually tested, how it compares with minoxidil, how to use rosemary oil on the scalp more safely, and when to stop and get advice.
Where the rosemary oil hype comes from
Almost every "rosemary oil works" video traces back to one paper: Panahi and colleagues, 2015, in the journal Skinmed. It compared rosemary oil with 2% minoxidil in people with androgenetic alopecia (pattern hair loss, the gradual thinning that tends to run in families).
Here is what the published abstract says:
100 people took part, 50 on rosemary oil and 50 on 2% minoxidil.
The trial ran for six months, with checks at 3 months and 6 months.
Hair was counted using standardised close-up photos of the scalp.
At 3 months, neither group had a meaningful change in hair count.
At 6 months, both groups had more hair than at the start, and there was no significant difference between the two groups.
Scalp itching went up in both groups, but it was more common with minoxidil.
So the honest headline is "rosemary oil did about as well as low-strength minoxidil in one six-month trial". That is interesting. It is a long way from "rosemary oil regrows hair".
The limits of that study
A few things are worth knowing before you spend money.
It was small. One hundred people split into two groups is a modest trial. Results from small studies often shrink or vanish when someone repeats them with more people.
It was only single-blind. The study is indexed as single-blind, which means one side (usually the participants or the assessors, not both) did not know who got what. It had no placebo group, so we cannot say how much hair would have grown with a plain oil and regular scalp massage alone.
It appears to have been done in men. The PubMed record lists male participants only, and a 2024 review in Clinical, Cosmetic and Investigational Dermatology describes them as men aged 18 to 49. We have no trial showing the same result in women.
The product details are vague. The abstract does not say what strength of rosemary oil was used or how it was mixed, so you cannot copy the method from a high-street bottle.
It has not been properly repeated. A 2025 review of herbal remedies for hair loss in Skin Appendage Disorders still leans on that same 100-person trial. The authors say the evidence for natural remedies is uneven, with small samples, short treatment times and little long-term follow-up, and they call for larger, well-designed trials before anything can be confirmed.
Rosemary oil vs minoxidil
Minoxidil is a licensed treatment. The NHS hair loss treatments page lists it as one of the main treatments for male pattern baldness, and says it can also be used for female pattern baldness. The NHS is also clear that these treatments do not work for everyone, only work while you keep using them, and are not all available on the NHS.
Rosemary oil is not a licensed medicine for hair loss. The one head-to-head trial is a reason to keep watching the research. On its own, it is too weak to justify swapping a treatment that is working for you. If you already use minoxidil, talk to a pharmacist or your GP before you stop or change anything.
Does rosemary oil work for hair loss of every kind?
No study shows that. The trial looked at pattern hair loss only. Hair loss has many causes, and rosemary oil does nothing for most of them.
NI Direct lists temporary hair loss from illness, stress, cancer treatment, weight loss and iron deficiency. If your shedding comes from low iron or a thyroid problem, the fix is treating that cause. Our guide to why your hair might be falling out runs through 10 common causes.
How to use rosemary oil on the scalp more safely
There is no agreed dose for rosemary oil on the scalp, because the research does not give one. These steps are about lowering the risk of a reaction, not about getting a guaranteed result.
Never put neat (undiluted) essential oil on your skin. DermNet's page on allergic contact dermatitis to essential oils advises against applying neat oils directly, as this can make you allergic over time.
Mix a few drops into a plain carrier oil, or buy a ready-made product meant for the scalp, and follow the label.
Do a patch test first. Put a small amount of the diluted oil on a small area of skin and watch for redness or itching before you use it all over your scalp.
Keep it away from your eyes and any broken or sore skin.
Give it time. In the trial, nothing changed at 3 months, so judging it after a few weeks tells you very little.
If you are pregnant, breastfeeding, have sensitive skin or a scalp condition, ask a pharmacist before you start.
Rosemary oil side effects on the scalp
The same DermNet page says the most common signs of an essential oil allergy are itching, redness and scaling where the oil touched the skin, and the rash can spread further. People with eczema (atopic dermatitis) are listed among those at higher risk.
In the Panahi trial, scalp itching increased in both groups over six months. If your scalp becomes red, itchy, flaky or sore, stop using the oil. A flaky, itchy scalp can also be a separate condition, such as seborrhoeic dermatitis, and an oil can make that worse.
When to see a GP or a trichologist
NI Direct advises seeing your GP for sudden hair loss, bald patches, hair coming out in clumps, or an itching and burning scalp. It also suggests seeing a GP to find out the cause first, before paying a commercial clinic.
A trichologist looks closely at your hair and scalp and helps you work out what is going on and what is worth trying. For a wider look at the options, read what trichologists recommend for thinning hair.
Frequently asked questions
How long does rosemary oil take to work for hair growth?
In the 2015 trial, neither rosemary oil nor minoxidil made a meaningful difference at 3 months. Both showed more hair at 6 months.
Is rosemary oil as good as minoxidil?
One small six-month trial in men found no significant difference between rosemary oil and 2% minoxidil. That is not enough evidence to call them equal.
Can I put rosemary oil straight on my scalp?
No. Neat essential oils can cause allergic contact dermatitis. Dilute it in a carrier oil and patch test first.
Does rosemary oil work for women?
We do not know yet. The main trial appears to have included men only.
Get your hair loss checked in Belfast
If you are not sure why your hair is thinning, a proper look at the cause is a better first step than another bottle of oil. Book a £30 hair loss consultation with Theresa Anthony at 77a Botanic Avenue, see our treatments and prices, or call 028 9096 4731.
Sources: Panahi et al. 2015, Skinmed (PubMed) · Bin Rubaian et al. 2024, Clinical, Cosmetic and Investigational Dermatology · Ahmed et al. 2025, Skin Appendage Disorders · NHS: hair loss treatments · NI Direct: hair loss · DermNet: allergic contact dermatitis to essential oils
About the author: Theresa Anthony is the trichologist at Tess Hair and Scalp Clinic, 77a Botanic Avenue, Belfast BT7 1JL, where hair loss treatment and a full hair salon sit under one roof. More about Theresa.
Written with AI help using the sources above, then checked by Theresa Anthony or her team before it went live.
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