Hair count up at 6 months, as with 2% minoxidil
Clinical trialRosemary oil vs 2% minoxidil6 months50 + 50 participantsRandomized, no placebo group
In people with androgenetic hair shedding, the hair count did not change significantly at 3 months. At 6 months it had increased in both groups, with no difference between them. Scalp itching increased in both groups, more with minoxidil. Without a placebo group, the trial cannot say how much is due to the oil1.
A place among seven non-conventional products
Review2025 network meta-analysis24 trialsHair density at 24 weeks
Rosemary oil applied to the scalp is among the non-conventional products compared with reference products. The authors give relative efficacy benchmarks; the abstract does not quantify the one for rosemary2.
Limited evidence, according to the reviews
Review2025 and 2026 reviews
The 2025 review notes small, short studies with no long follow-up and calls for larger randomized trials3. The 2026 review, focused on rosemary, calls for documenting its long-term efficacy and safety4.