The 15-second version
- In a six-month randomized trial of 100 men with pattern hair loss, hair counts rose significantly with a rosemary oil lotion, about the same as with 2% minoxidil.1
- A 2025 trial found two rosemary oil blends improved hair growth rate, thickness and density over 90 days, compared with coconut oil.2
- In lab tests, rosemary leaf extract blocked 5-alpha-reductase, the enzyme that makes DHT, and it improved hair regrowth in mice.3
- The 2015 trial’s authors describe rosemary oil as antioxidant and antimicrobial, with conditioning properties, and suggest it may improve blood flow to the scalp.1
- Dilute rosemary essential oil and patch-test it before using it on your scalp.4
Why rosemary has so much attention in hair care
Rosemary oil became one of the most talked-about hair care ingredients on social media in the early 2020s. A 2021 review written for dermatologists listed rosemary among the most common “hairfluencer” hair growth trends.6 Scientists have studied it for good reasons. Rosemary oil is rich in aromatic compounds such as 1,8-cineole and camphor, and the authors of the main hair trial describe it as antioxidant and antimicrobial, with nourishing and conditioning properties that leave hair strands looking softer and silkier.1
Rosemary shows up in four forms, and each has been used differently.
| Form | How it’s made | What it contains | Where it appears |
|---|---|---|---|
| Essential oil | Steam-distilled from the leaves and flowering tops | Volatile compounds such as 1,8-cineole, camphor, borneol and pinene1 | The 2015 and 2025 hair trials12 |
| Leaf extract | Leaves soaked in a solvent, then concentrated | Compounds such as carnosic acid and its relatives3 | The 2013 lab and mouse research on hair growth3 |
| Infused oil | Dried leaves steeped in a carrier oil | Mostly the carrier oil, with small amounts of rosemary compounds | Home preparations |
| Rosemary water | Leaves simmered or steeped in water | Water-soluble compounds | Home preparations |
The 2015 trial: rosemary oil and 2% minoxidil
Almost every article on rosemary oil for hair cites one study, published in the journal SKINmed in 2015.1 We read the full paper.
The trial enrolled 100 men with pattern hair loss (androgenetic alopecia) at a hospital dermatology clinic in Tehran, Iran. Half used a rosemary oil lotion and half used 2% minoxidil. Each man applied his lotion to the front, top and crown of his scalp twice a day, with gentle massage, for six months.1
Results were measured with standardized close-up photos at the start, at 3 months and at 6 months. Two dermatologists counted the hairs without knowing who used which lotion.1
By 6 months, hair counts had risen significantly in both groups compared with the start. The rosemary group and the minoxidil group did not differ significantly, so the two lotions performed about the same.1 Men in the rosemary group also rated their reduction in hair loss slightly better than the minoxidil group did. Dry hair, greasy hair and dandruff did not change, and scalp itching was the main side effect, reported in both groups.1
How rosemary may work
What the 2015 trial’s authors suggested
The authors proposed that rosemary oil may relax small vessels in the scalp and increase the blood supply to hair follicles. They also pointed to its antioxidant activity, since oxidative stress has been linked to hair loss.1
Lab and mouse research on leaf extract
A 2013 study tested rosemary leaf extract on mice whose hair regrowth had been interrupted by testosterone. The extract improved regrowth, and it also promoted hair growth in shaved mice.3 In lab tests, it inhibited 5-alpha-reductase, the enzyme that turns testosterone into DHT, by 82% to 95% at the concentrations tested. The researchers identified 12-methoxycarnosic acid as an active compound.3
What reviews say
A 2025 review concluded that rosemary may benefit several types of hair loss through improved blood flow, anti-inflammatory activity and antioxidant effects. It described rosemary as a cost-effective natural option with potential alongside conventional treatments.9
More research on rosemary
A 2025 trial of rosemary blends
In a 2025 trial, 90 healthy adults aged 18 to 55 used one of three oils for 90 days: a rosemary and lavender blend, a rosemary and castor oil blend, or coconut oil. Neither participants nor assessors knew which oil was which.2
Both rosemary blends improved hair growth rate, thickness, density and length, and reduced hair fall, compared with coconut oil. Growth rate rose from 0.22 to 0.34 mm a day in the rosemary and lavender group, and from 0.23 to 0.33 mm a day in the rosemary and castor oil group.2
An essential oil blend in alopecia areata
A 1998 trial gave people with alopecia areata, an autoimmune type of patchy hair loss, a blend of thyme, rosemary, lavender and cedarwood oils to massage into the scalp every night. After seven months, 44% of that group had improved, compared with 15% of those using carrier oils alone.8
What researchers want to learn next
Reviews of the research call for larger, longer randomized trials to confirm the benefits and safety of rosemary oil.9 The 2015 trial enrolled men, and studies in women would add to the picture.
Rosemary oil and minoxidil
The two are compared head to head in the 2015 trial. This table sets them side by side.
| Measure | Rosemary essential oil | Topical minoxidil |
|---|---|---|
| What it is | A natural essential oil, used in cosmetics and traditional preparations | An approved topical hair loss medication, sold without a prescription in Canada |
| Human research on hair | A six-month trial in 100 men1 and a 90-day trial of rosemary blends2 | Many placebo-controlled trials. Recommended in European guidelines for men and women.10 |
| Strengths studied | A lotion standardized for cineole1 | 2% and 5%10 |
| When results appeared | By six months in the 2015 trial1 | Several months10 |
| Side effects reported | Scalp itching1 | Scalp itching and irritation110 |
If you’ve been diagnosed with pattern hair loss, your doctor or pharmacist can explain your options, including minoxidil, which has the longest research record.
Using rosemary oil on your scalp
The 2015 trial applied rosemary oil lotion to the scalp twice a day with gentle massage for six months.1 Massage may add its own benefit. In a 2016 study, nine men who had a standardized four-minute scalp massage every day for 24 weeks showed an increase in hair thickness.7
Rosemary oil is concentrated, so a few habits keep it comfortable to use.
- Dilute it. The European Medicines Agency’s guidance for rosemary oil skin products uses preparations of 6 to 10% oil, for muscle and joint aches.5
- Keep it out of your eyes.45
- Patch-test first, since some people react to rosemary. Put a little diluted oil on your inner arm and wait 24 to 48 hours.4
- Never swallow it, and store it away from children. Rosemary oil contains camphor, which is harmful if swallowed.4
- Ask your doctor or pharmacist first if you’re pregnant or breastfeeding, have epilepsy, or want to use it on a child. The European guidance doesn’t recommend rosemary oil products for anyone under 18.5
Stop using it if your scalp itches, burns or flakes.
Rosemary water and rosemary in shampoo
Rosemary water
Rosemary water is a popular home rinse, made by steeping or simmering rosemary leaves in water. The hair research in this article used rosemary oil and leaf extract, so those are the forms it covers.
Rosemary in our shampoo
HUSSSH Hair Therapy Shampoo contains rosemary leaf oil, along with eight other plant oils and extracts. We include rosemary for its fresh, herbal scent and the clean, refreshed feel it gives the scalp. The hair trials above used leave-on rosemary products, and none of them tested our shampoo, which is a rinse-off cosmetic. See the full ingredient list.
Frequently asked questions about rosemary oil for hair
In the 2015 trial, the increase in hair count showed at the six-month check, so the research looked at consistent use over several months.1
Ask your pharmacist or doctor. Both can irritate the scalp in some people, so it helps to start one at a time.1
Rosemary water is a different preparation, made by steeping leaves in water. The hair research in this article used the oil and leaf extract, so those are the forms it covers.
The European Medicines Agency's guidance for rosemary oil skin products uses preparations of 6 to 10% oil.5 Patch-test first, keep it out of your eyes, and stop if your scalp itches or burns.
References
- Panahi Y, Taghizadeh M, Marzony ET, Sahebkar A. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. SKINmed. 2015;13(1):15-21. PubMed ↩
- Patel S, et al. Rosmagain™ as a natural therapeutic for hair regrowth and scalp health: a double-blind, randomized, three-armed, placebo-controlled clinical trial. Cureus. 2025;17(6):e85906. doi:10.7759/cureus.85906 ↩
- Murata K, Noguchi K, Kondo M, et al. Promotion of hair growth by Rosmarinus officinalis leaf extract. Phytother Res. 2013;27(2):212-217. doi:10.1002/ptr.4712 ↩
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Rosmarinus officinalis L., aetheroleum and Rosmarinus officinalis L., folium (revision 1). EMA ↩
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Rosmarinus officinalis L., aetheroleum (revision 1). EMA ↩
- Paiewonsky B, Heinen N, Hordinsky M, Sadick N, Farah RS. Hairfluencer social media trends every dermatologist should know in 2021. J Cosmet Dermatol. 2023;22(2):669-670. doi:10.1111/jocd.15123 ↩
- Koyama T, Kobayashi K, Hama T, Murakami K, Ogawa R. Standardized scalp massage results in increased hair thickness by inducing stretching forces to dermal papilla cells in the subcutaneous tissue. Eplasty. 2016;16:e8. PubMed ↩
- Hay IC, Jamieson M, Ormerod AD. Randomized trial of aromatherapy: successful treatment for alopecia areata. Arch Dermatol. 1998;134(11):1349-1352. PubMed ↩
- Alawadh RM, Alsherian SN, Al-Husain KM, et al. Unlocking the potential of rosemary in alopecia: a narrative review of evidence on mechanism, applications and challenges. J Adv Trends Med Res. 2025;2(4):649-653. doi:10.4103/ATMR.ATMR_141_25 ↩
- Kanti V, Messenger A, Dobos G, et al. Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men, short version. J Eur Acad Dermatol Venereol. 2018;32(1):11-22. PubMed ↩
This article is for general information only and is not medical advice. Talk to your doctor or a dermatologist about any hair loss. HUSSSH® Hair Therapy products are cosmetics. They are not intended to diagnose, treat, cure or prevent any disease, including hair loss. The studies referenced above used specific extracts, concentrations and methods that differ from rinse-off hair care products. HUSSSH Hair Therapy Shampoo contains rosemary leaf oil. None of the studies in this article tested our shampoo, and we don’t claim it treats hair loss.
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