Rosemary oil vs minoxidil: what the experts say

Minoxidil, by a wide margin. It has a Guru Score above 90%, while rosemary oil sits at about 40%, and of the experts in both our guides, six rated minoxidil higher and only one rated rosemary oil higher. Even the experts who like rosemary oil mostly treat it as an extra, or as a fallback for a scalp that cannot take minoxidil, rather than a swap. The one trial behind rosemary oil matched it against 2% minoxidil, the weaker of the two strengths sold over the counter.

Below is how the two differ, how the experts who reviewed both rated them, what that famous trial did and did not show, which is easier on the scalp, and what to know before starting either one.

What is the difference between rosemary oil and minoxidil?

One is a plant oil and the other is a medicine. Rosemary oil is the essential oil of the rosemary plant, the same herb you cook with, and people massage it into the scalp in the hope of slowing hair loss (Bin Rubaian and colleagues). Minoxidil started life as a blood pressure tablet that grew hair as a side effect (US label). On the scalp, as a liquid or a foam at 2% or 5%, it is approved to regrow hair in hereditary hair loss (US label).

The reasons people give for rosemary oil are mostly lab reasons. The claim that it blocks DHT, the hormone behind pattern hair loss, comes from test tube and mouse studies of a rosemary leaf extract, not from people using the oil (Murata and colleagues). Minoxidil has decades of trials in people behind it. Dr Dray, a dermatologist, calls minoxidil “the most evidence-based hair loss treatment that you could buy without a prescription.”

Minoxidil on the scalp is sold without a prescription in the US and the UK (US label, UK label). Minoxidil tablets are a different matter: they are a prescription blood pressure medicine, so they need a doctor (US label).

Which do the experts rate higher, rosemary oil or minoxidil?

Minoxidil. It has a Guru Score above 90% from more than 15 experts, and nobody said no to it. Rosemary oil has a Guru Score of about 40% from more than a dozen experts, and they are split down the middle, with as many saying no as saying yes.

The fairest test is the experts in both our guides. Six of them, all dermatologists, rated minoxidil higher: Dr Dray, Dr. Aanchal MD, Dr. Daniel Sugai and Dr. Sam Ellis said no to rosemary oil, and Dr. Jenny Liu and Dr. Mamina were mixed on it. Four said yes to both. Only one, Cassandra Bankson, a medical esthetician, rated rosemary oil higher.

Every verdict, with a link to the moment each expert gave it, is in our rosemary oil guide and minoxidil guide.

Is rosemary oil as good as minoxidil for hair loss?

Not on the evidence we have. Nearly the whole case for rosemary oil rests on one trial. In 2015, researchers gave 100 people with pattern hair loss either rosemary oil or 2% minoxidil for six months. Neither group had changed at three months, and at six months both had more hair, with no significant difference between them (Panahi and colleagues). The trial had no placebo group, so it cannot say how much of the gain either treatment caused, and a later review describes the people in it as men aged 18 to 49 (Bin Rubaian and colleagues).

The bigger catch is the yardstick. In a 48 week trial in 393 men, 5% minoxidil regrew 45% more hair than 2% (Olsen and colleagues). Dr. Jenny Liu, a dermatologist, says: “That study compared rosemary oil to 2% minoxidil and we do know 5% works best.” Dr. Mamina, also a dermatologist, adds: “I have a feeling that the 5% minoxidil would outperform rosemary oil.” Dr Dray puts it bluntly: “rosemary oil is as useless as 2% minoxidil and can burn your scalp.”

The other doubters point to how little else there is. Dr. Sam Ellis, a dermatologist, says that “at best there's strong anecdotal evidence for these things, but if you look at the scientific literature these oils don't really seem to help.” Dr. Aanchal MD thinks rosemary oil “has a bit of a placebo effect.” And Dr Dray suspects that “a lot of people are just getting the benefits of scalp massage and they're attributing it to the oil,” which a tiny study of scalp massage alone makes at least possible (Koyama and colleagues).

For women, minoxidil has the firmer footing. A Cochrane review found evidence for it in female pattern hair loss, though much of it was of moderate to low quality (Cochrane), and a once-a-day 5% foam is sold for women in the US and the UK (US label, UK label). The rosemary oil trial was in men.

Why do some experts still like rosemary oil?

Mostly as an extra, not a replacement. Dr. Shereene Idriss, a dermatologist who said yes to both, calls it “a nice adjunct to use,” and adds that “you have to use it twice a day, not just once a day, for at least six months to see full effect.” Doctorly, a channel run by two dermatologists, put it plainly: “Don't ditch your minoxidil for the Rosemary Oil.”

Others see it as a fallback for a scalp that cannot cope with minoxidil. Dr. Somji Skin, a cosmetic surgeon, says: “If you got a sensitivity to Minoxidil then you can use rosemary oil instead.” Even Dr. Daniel Sugai, who said no to rosemary oil, would only consider it for someone who is “not able to tolerate even the foam,” and he is “still not convinced that it does a good job at regrowing hair.”

Cassandra Bankson, the one expert who rated rosemary oil higher, says it may be “a great budget option or a great cruelty free option to things like Rogaine or minoxidil that you might not want to use.” One of her doubts about minoxidil is staying power: she notes that “when you stop using the minoxidil the hair falls out.” Doctor Youn, a plastic surgeon who said yes to both, says of the trial that “when you compare topical rosemary oil to Minoxidil the results were almost identical,” though that trial used the 2% strength.

Which is gentler on the scalp, rosemary oil or minoxidil?

Rosemary oil itched less in the trial, but it is not free of trouble. Scalp itching rose in both groups, and it was more common with minoxidil at three and six months (Panahi and colleagues). Rosemary is a known, if uncommon, cause of allergic skin reactions (González-Mahave and colleagues), and across essential oils most of those reactions come from pure oils or strong products (de Groot and Schmidt). Doctorly warn: “You definitely don't want to use 100% pure Rosemary Oil because it is an essential oil that can irritate the scalp.” They suggest diluting it in a carrier oil.

With minoxidil, itching and irritation are the common side effects, along with an early shed in the first weeks for many people (UK label). The liquid is often the culprit: propylene glycol caused most of the reactions in people patch tested after reacting to minoxidil liquid (Friedman and colleagues), and the foam was made without it (Olsen and colleagues, 2007). So if the liquid makes your scalp itch, the foam may suit you better.

Minoxidil also has to be lived with. It only works while you use it: stop, and you will probably lose the regrown hair within three to four months (US label). Dr. Daniel Sugai warns that “your hair is going to fall out and go back to baseline.” It is also dangerous to cats and dogs: in poison centre cases, cats were mostly exposed by licking an owner's skin or pillowcase (Tater and colleagues).

Can you use rosemary oil and minoxidil together?

The experts disagree, and we found no trial of the pair. Doctorly suggest “just use them together because they could have potential benefits together,” while Dr. Somji Skin warns that combining the two untested could go badly. If you want to try both, it may be worth asking your doctor first and keeping minoxidil as the treatment you rely on.

It also helps to know what kind of hair loss you have. The NHS suggests seeing a GP to find the cause (NHS), and shedding after illness, stress or childbirth often grows back by itself, which can make any oil look as if it worked (DermNet).

Can you use rosemary oil or minoxidil while pregnant?

Ask a doctor first. The US minoxidil labels say it may be harmful in pregnancy and breastfeeding (US label), and the UK label says it should not be used then (UK label). For rosemary oil on the scalp, our guide found no studies in pregnancy or breastfeeding, so the research is limited. Anyone who is pregnant, breastfeeding or trying for a baby may want to talk to their doctor or midwife before starting either one.