Rosemary oil for hair growth: worth the hype?
One study launched a million 90-day videos. Here is what it actually found.
- By
- Evi Editorial
- Published
- Last reviewed
Rosemary oil is the hair-growth ingredient of the moment, carried by before-and-after videos and a single claim: that it regrows hair as well as minoxidil.
The one study behind the claim
The claim traces to a 2015 randomised trial in men with pattern hair loss. After six months, both the rosemary group and the 2% minoxidil group gained hair count, and rosemary caused less scalp itching. That is encouraging. It is also one modest-quality study, comparing against the weaker strength of the standard drug.
Trace this claim “Regrows hair as well as minoxidil.”
01 · Ingredient
PromisingOne 2015 trial in men with pattern hair loss found rosemary oil matched 2% minoxidil at six months. It is a single, modest-quality study — promising, not settled.
02 · Supporting studies (2)
- Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial — SKINmed / PubMed, 2015. Both groups gained hair count at 6 months; rosemary caused less scalp itching.
- Can Plant Extracts Help Prevent Hair Loss or Promote Hair Growth? A Review Comparing Their Therapeutic Efficacies, Phytochemical Components, and Modulatory Targets — Molecules (PMC), 2024. A review of plant extracts found that several have shown hair growth-promoting efficacy in clinical trials by modulating cellular pathways and growth factors.
03 · Products with Rosemary oil
No other catalogue product lists this ingredient yet.
Changes
— We rewrote the one-line summary of a cited study. A source-by-source audit found the previous summary said more than, or something different from, what the study itself reports. See before and after
The rest of the bottle
Most viral scalp oils blend rosemary with peppermint and castor oil. Neither has comparable human evidence: the famous peppermint result is a mouse study, and castor oil coats strands so hair looks glossier without any trial showing growth.
Trace this claim “Thickens and lengthens hair.”
01 · Ingredient
UnsupportedNo human trials support growth. It coats strands so hair looks glossier and heavier, and heavy use is linked to matting in some case reports.
02 · Supporting studies (2)
- Hair cosmetics: an overview — International Journal of Trichology (PMC), 2015. This overview article reviews the formulations and mode of action of various hair cosmetics, including shampoos, conditioners, and hair dyes.
- Use of Castor Oil in Dermatology: A Narrative Review — Cureus (PMC), 2026. Reviews castor oil's skin and hair uses and the limited clinical evidence behind them.
03 · Products with Castor oil
No other catalogue product lists this ingredient yet.
Changes
— We rewrote the one-line summary of a cited study. A source-by-source audit found the previous summary said more than, or something different from, what the study itself reports. See before and after
Better lighting, a fresh haircut and three months off heat styling will flatter any 90-day video.
The verdict
Cheap and low risk, with one promising human study. Reasonable to try for six months — but if you are treating real hair loss, see a doctor rather than relying on an oil.
References
- Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. SKINmed / PubMed, 2015.
- Can Plant Extracts Help Prevent Hair Loss or Promote Hair Growth? A Review Comparing Their Therapeutic Efficacies, Phytochemical Components, and Modulatory Targets. Molecules (PMC), 2024.
- Hair cosmetics: an overview. International Journal of Trichology (PMC), 2015.
- Use of Castor Oil in Dermatology: A Narrative Review. Cureus (PMC), 2026.