Rosemary Oil vs. Minoxidil: What the Clinical Research Actually Shows

Phase Theory Research

February 28, 2026 · 8 min read · Updated October 1, 2026

Rosemary Oil vs. Minoxidil: What the Clinical Research Actually Shows

Search for rosemary and hair growth and you'll find the same confident claim everywhere: rosemary works just as well as minoxidil. Behind that claim sits one small randomized trial — and a great deal of repetition. Here's what the research actually showed, what it can't tell us, and how to think about rosemary honestly.

The Study Behind the Headlines

In 2015, researchers published a randomized comparative trial (Panahi and colleagues, in the journal SKINmed) that enrolled 100 people with androgenetic alopecia — the common hereditary pattern of hair thinning. Half applied rosemary oil twice daily; half applied a 2% minoxidil solution twice daily. The trial ran for six months, with the two treatments compared directly against each other. There was no placebo group.

At the three-month mark, neither group showed a statistically significant change in hair count. By six months, both groups improved significantly over their own starting points — and there was no statistically significant difference between the rosemary and minoxidil groups. The one measure that clearly separated the groups was scalp itching, reported by fewer participants using rosemary oil.

What That Trial Does — and Doesn't — Prove

The trial's finding is genuinely interesting: a botanical preparation performed comparably to minoxidil 2% on hair count over six months. But it is one trial, not a settled answer. It compared rosemary against the 2% minoxidil formulation — not the 5% formulation many adults are advised to use. It ran for six months, a short window for a condition that progresses over years. And it tested one specific rosemary oil preparation, not rosemary in every form it's sold.

"Comparable in one trial" is not the same as "equivalent to minoxidil." Minoxidil has decades of research behind it and is an approved drug for pattern hair loss. Rosemary's human evidence is far thinner — which is exactly why this article distinguishes what's demonstrated from what's hoped.

How Minoxidil Works — and How Rosemary Might

Minoxidil is a potassium channel opener. Its precise mechanism still isn't fully understood, and the popular shorthand that it "works by increasing blood flow" oversimplifies it. It's a regulated drug with a defined therapeutic claim, available over the counter in many countries.

Rosemary's case rests mostly on laboratory research. In cell and animal studies, Rosmarinus officinalis leaf extract has been shown to inhibit 5-alpha reductase — the enzyme that converts testosterone into DHT, the hormone involved in follicle miniaturization — by 82.4% and 94.6% at high laboratory concentrations. That's a meaningful signal from the bench. But laboratory concentrations don't translate directly to a human scalp, and no human trial has confirmed that enzyme inhibition is how rosemary behaves on a real head of hair.

Cosmetic Botanicals Are Not Drug Treatments

This distinction matters to us as a company. Minoxidil is an approved treatment for hair loss with an evidence-based therapeutic claim. Rosemary as used in cosmetic products — including ours — is chosen to support a healthy scalp environment. Cosmetic products are not treatments for hair loss, and we don't present them as one.

If you're noticing progressive or patterned thinning, the most useful step isn't an oil — it's a diagnosis. A dermatologist or other qualified clinician can identify what's actually happening and walk you through evidence-based options, including approved medications.

If You Use Rosemary Anyway, Use It Well

None of this makes rosemary uninteresting. It's one of the more studied botanicals in scalp care, and the 2015 trial kept interest alive for good reason. Reasonable practice: dilute properly, patch test before your first full application, be consistent for months before judging, and stop if your scalp becomes irritated. Rosemary is a sensible part of a cosmetic hair and scalp care routine.

One good trial makes a botanical interesting. It doesn't make it a drug.

Frequently Asked Questions

Is rosemary oil as effective as minoxidil?

One six-month randomized trial found rosemary oil comparable to minoxidil 2% on hair count in androgenetic alopecia, with both groups improving over baseline. That's an encouraging result — and a good reason for more research, not a firm claim of equivalence.

Does rosemary block DHT?

Laboratory and animal studies have shown rosemary extract inhibiting 5-alpha reductase, the enzyme that converts testosterone to DHT, at high concentrations. That result comes from the lab, not from human trials, so it's accurate to say rosemary is 'studied for' DHT-related mechanisms rather than that it 'blocks DHT' in people.

Can rosemary oil regrow hair?

There is no reliable evidence that a cosmetic oil regrows hair. The six-month trial and the laboratory research are promising starting points — not proof of regrowth.

Do Baby Hair® products treat hair loss?

No — and we don't claim they do. Baby Hair® products are cosmetics formulated to support scalp comfort and a healthy scalp environment, and rosemary appears in them for exactly that purpose.

References & Further Reading

Panahi Y, Taghizadeh M, Marzony ME, Sahebkar A. "Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial." SKINmed. 2015;13(1):15–21.

"Promotion of hair growth by Rosmarinus officinalis leaf extract" (laboratory and animal study of 5-alpha reductase inhibition). PubMed: 22517595.

"An Overview of Commonly Used Natural Alternatives for the Treatment of Androgenetic Alopecia, with Special Emphasis on Rosemary Oil." Clinical, Cosmetic and Investigational Dermatology. 2024.