Rosemary oil vs minoxidil: what the one trial really showed, and four ‘hair growth’ bottles graded

The short version

• The viral claim comes from one trial. In 2015, Panahi et al. randomised 100 people with androgenetic (pattern) hair loss to rosemary oil or 2% minoxidil for six months. Both groups gained hair at six months (not at three), with no significant difference between them. [1]
• There was no placebo group. So the trial shows rosemary oil did about as well as 2% minoxidil in that group. It can’t show how much of either effect was the treatment. The minoxidil arm also used the lower 2% strength, not the 5% that’s standard for men today. [1][2]
• A 2025 network meta-analysis of male pattern hair loss treatments included rosemary oil. Panahi 2015 was the only rosemary trial in its table of 24 studies. [3]
• 5% minoxidil foam has placebo-controlled evidence (352 men, 16 weeks) and is an FDA-regulated OTC drug. [2][4]
• Most “rosemary for hair growth” bottles don’t tell you how much rosemary is in them.

Product	Scope Grade	Why	Buy
Men’s Rogaine 5% Minoxidil FoamBuy on Amazon: Rogaine Men’s Rogaine 5% Minoxidil Foam (opens in a new tab)	A	Placebo-controlled trial behind the regrowth claim; FDA drug label	Buy on Amazon: Rogaine Men’s Rogaine 5% Minoxidil Foam (opens in a new tab)
Mielle Rosemary Mint Scalp & Hair OilBuy on Amazon: Mielle Rosemary Mint Scalp & Hair Oil (opens in a new tab)	C	Cosmetic wording; rosemary is one of many oils, dose unknown	Buy on Amazon: Mielle Rosemary Mint Scalp & Hair Oil (opens in a new tab)
The Ordinary Multi-Peptide Serum for Hair DensityBuy on Amazon: The Ordinary Multi-Peptide Serum for Hair Density (opens in a new tab)	C	Supplier actives with small, mostly industry data; cosmetic “denser-looking” wording	Buy on Amazon: The Ordinary Multi-Peptide Serum for Hair Density (opens in a new tab)
Botanic Hearth Rosemary Oil for Hair Growth	D	“For Hair Growth” in the name; rosemary listed sixth of seven	No verified Amazon listing

Products we read

As an Amazon Associate, FORMUSCOPE earns from qualifying purchases. Prices live on Amazon and change often, so we don’t show them. Links never change a grade.

D-graded products get no buy link, by policy.

Our read for most people: if you’re dealing with pattern hair loss, the product with real evidence is 5% minoxidil, ideally after a conversation with a dermatologist about the cause. If you just like a scalp oil, Mielle at least keeps its wording cosmetic. Don’t buy any bottle because it says “hair growth” next to rosemary.

---

The trial, read properly

Panahi Y, et al., 2015 (Skinmed). [1]

What they did	What it means
100 patients with androgenetic alopecia, randomised 50/50	A real randomised trial, but small
Rosemary oil vs minoxidil 2%, 6 months	Active comparator, no placebo
Hair counts by standardised microphotographs at 0, 3 and 6 months	Objective outcome, good
No change at 3 months in either group; both up at 6 months; no difference between groups	“Rosemary = minoxidil 2%” in this sample
Scalp itching rose in both groups, more with minoxidil	Rosemary was better tolerated

The abstract doesn’t state the rosemary oil concentration or product, so no retail bottle can claim to match the trial dose. The 2025 network meta-analysis lists the trial’s participants as young (mean age about 25 in the rosemary arm), which also limits how far it generalises. [3]

What about mechanism? In mice, a rosemary leaf extract improved hair regrowth after testosterone treatment and inhibited 5α-reductase in the test tube. [5] That’s interesting biology, but it’s an extract in animals, not an oil on human scalps.

The benchmark. In the 2007 Olsen trial, 352 men used 5% minoxidil foam or placebo for 16 weeks. Hair counts and the men’s own ratings improved significantly versus placebo, and the foam was well tolerated over 52 weeks. [2]

---

Product by product

1. Men’s Rogaine 5% Minoxidil Foam: Scope Grade A (Well supported)

The claim (Amazon listing, sold by Amazon.com, captured Nov 13, 2026): “scientifically proven to regrow hair & reverse the progression of hereditary hair loss”; “clinically proven to improve hair regrowth by 4x in 16 weeks* *vs control with continued use”.

The formula (Drug Facts on the listing [4]): Active ingredient: Minoxidil 5% w/w (without propellant). Inactive ingredients: butane, butylated hydroxytoluene, cetyl alcohol, citric acid, glycerin, isobutane, lactic acid, polysorbate 60, propane, purified water, SD alcohol 40-B, stearyl alcohol

Check	Finding	Effect
Study type	Double-blind, placebo-controlled RCT of 5% minoxidil foam, n=352, 16 weeks [2]	Base A
Concentration match	5% on the label = 5% in the trial	Match
Regulatory	Sold as an OTC drug with Drug Facts	OK
Claim match	“Regrow hair” for hereditary hair loss matches the trial. “4x” is a brand figure we couldn’t trace to a published table	Small caveat

Worth knowing: it only works while you keep using it (“with continued use” is in the brand’s own footnote), and it’s for hereditary thinning, not other kinds of hair loss.

---

2. Mielle Organics Rosemary Mint Scalp & Hair Oil with Biotin: Scope Grade C (Plausible, thin evidence)

The claim (Amazon listing, sold by Mielle Organics, captured Nov 13, 2026): “Powered by rosemary oil & biotin to help invigorate the scalp and enhance circulation”; “the biotin-rich blend makes it a go-to for those looking to encourage natural thickness.”

The formula (INCI on the same listing [6]): soybean oil, castor oil, then rosemary leaf oil (third), followed by jojoba, peppermint, eucalyptus, tea tree, lavender, basil, patchouli and sage oils, menthol and benzyl nicotinate, with biotin far down the list.

Check	Finding	Effect
Study type	Rosemary evidence = one non-placebo trial [1]; no trial of this product found	C at best
Concentration match	Rosemary oil’s percentage isn’t disclosed	Can’t match dose
Formula notes	Eight fragrant essential oils plus menthol: a lot of potential irritants for a scalp product	Caution for sensitive scalps
Claim match	“Invigorate”, “encourage natural thickness” are cosmetic phrases, not regrowth claims	Fair wording

---

3. The Ordinary Multi-Peptide Serum for Hair Density: Scope Grade C (Plausible, thin evidence)

The claim (Amazon listing, sold by Amazon.com, captured Nov 13, 2026): “designed to promote thicker, fuller, and denser-looking hair by supporting the scalp”; formulated with “REDENSYL, Procapil, CAPIXYL, BAICAPIL, AnaGain, and High-Solubility Caffeine”.

The formula (INCI via INCIDecoder [7]): caffeine fifth, then biotinoyl tripeptide-1, acetyl tetrapeptide-3, larch wood, pea, skullcap root, wheat germ, soy germ, red clover and green tea extracts, apigenin and oleanolic acid. These are the INCI components behind the trade names above.

Check	Finding	Effect
Study type	Best independent-ish data we found: a single-blind, vehicle-controlled trial of a lotion with Redensyl plus Sepicontrol A5 (n=44, 24 weeks) [8]. Not this formula	C
Concentration match	No percentages disclosed for any trade active	Can’t match dose
Claim match	“Denser-looking” is careful cosmetic wording	OK

---

4. Botanic Hearth Rosemary Oil for Hair Growth: Scope Grade D (Weak or undercut by formula)

The claim (Amazon listing, sold by Botanic Hearth, captured Nov 13, 2026): the product name is “Rosemary Oil for Hair Growth“, and the listing says it “helps stimulate hair follicles to encourage healthy, thicker and faster hair”.

The formula (INCI via INCIDecoder [9]): Grape Seed Oil, Jojoba Oil, Sesame Oil, Castor Oil, Vitamin E (Tocopherol), Rosemary Oil (Rosmarinus Officinalis), Biotin

Check	Finding	Effect
Formula vs claim	Rosemary is sixth of seven, after vitamin E. Its share isn’t disclosed, and below 1% the order isn’t meaningful [10]	Undercuts a product named for it
Study type	One non-placebo trial of an unknown rosemary dose [1]	Thin
Claim match	“Faster hair” goes beyond anything the trial measured	Overclaims

No buy link (our policy for D grades).

---

• Claimed / hero active
• Fragrance & allergens
• Carrier oils
• Everything else

Rogaine 5% Foam 13 ingredients

• #1 Minoxidil

Mielle Rosemary Mint 32 ingredients

• #1 Glycine Soja (Soybean) Oil
• #2 Ricinus Communis (Castor) Seed Oil
• #3 Rosmarinus Officinalis (Rosemary) Leaf Oil
• #4 Simmondsia Chinensis (Jojoba) Seed Oil
• #5 Mentha Piperita (Peppermint) Oil
• #6 Eucalyptus Globolus (Eucalyptus) Leaf Oil
• #7 Menthol
• #8 Melalueca Alternifolia (Tea Tree) Leaf Oil
• #12 Lavandula Angustifolia (Lavender) Oil
• #28 Ocimum Basilicum (Basil) Oil
• #29 Pogostemon Cablin (Patchouli) Oil
• #30 Salvia Officinalis (Sage) Oil

The Ordinary Hair Density 36 ingredients

• #5 Caffeine
• #6 Biotinoyl Tripeptide-1
• #7 Acetyl Tetrapeptide-3

Botanic Hearth 7 ingredients

• #1 Grape Seed Oil (Vitis Vinifera)
• #2 Jojoba Oil (Simmondsia Chinensis)
• #3 Sesame Oil (Sesamum Indicum)
• #4 Castor Oil (Ricinus Communis)
• #6 Rosemary Oil (Rosmarinus Officinalis)

Each square is one ingredient, in label order. Original FORMUSCOPE graphic. Hover or tap a square for its name.

Each square is one ingredient in label order. Above 1%, US labels list ingredients in descending order; at 1% or less, order is free. [10]

How to read a “hair growth” label in 20 seconds

1. Drug Facts box or not? A product that legally claims to regrow hair in the US carries Drug Facts with an active ingredient and strength (e.g. Minoxidil 5%). Cosmetics should say “thicker-looking” or “fuller-looking”.
2. Find the hero ingredient’s position. If it’s after vitamin E or the preservative, it’s probably a small amount.
3. Count the fragrant oils (peppermint, tea tree, eucalyptus, lavender) if your scalp is sensitive.
4. Give anything 6 months. In the one rosemary trial, neither group showed a hair-count change at 3 months. [1]

When to see a professional

See a board-certified dermatologist if hair loss is sudden, patchy, comes with scalp pain, redness or scaling, or follows illness, a new medicine or childbirth. Pattern hair loss in women and men has prescription options that no oil replaces, and the cause matters. If you’re pregnant or breastfeeding, ask your doctor before using minoxidil. FORMUSCOPE grades cosmetic and OTC claims; we don’t give medical advice.

Sources

1. 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. [Human RCT · n=100 · 6 months · active comparator, no placebo] https://pubmed.ncbi.nlm.nih.gov/25842469/
2. Olsen EA, et al. A multicenter, randomized, placebo-controlled, double-blind clinical trial of a novel formulation of 5% minoxidil topical foam versus placebo in the treatment of androgenetic alopecia in men. J Am Acad Dermatol. 2007;57(5):767-74. [Human RCT · n=352 · 16 weeks + 52-week open-label safety] https://pubmed.ncbi.nlm.nih.gov/17761356/
3. Gupta AK, Bamimore MA, Talukder M. Relative efficacy of conventional monotherapies and select nonconventional, over-the-counter products for male androgenetic alopecia: a network meta-analysis study. J Cosmet Dermatol. 2025;24(10):e70483. [Network meta-analysis · 24 trials · Table 1 lists one rosemary trial] https://pubmed.ncbi.nlm.nih.gov/41051009/ · full text: https://europepmc.org/article/PMC/PMC12498493
4. Men’s Rogaine 5% Minoxidil Foam: Amazon listing (claims, Drug Facts). https://www.amazon.com/dp/B00198UH4Q (accessed Nov 13, 2026)
5. Murata K, et al. Promotion of hair growth by Rosmarinus officinalis leaf extract. Phytother Res. 2013;27(2):212-7. [Mice + in vitro] https://pubmed.ncbi.nlm.nih.gov/22517595/
6. Mielle Organics Rosemary Mint Hair Oil with Biotin, 2 oz: Amazon listing (claims, INCI). https://www.amazon.com/dp/B07N7PK9QK (accessed Nov 13, 2026)
7. INCIDecoder. The Ordinary Multi-Peptide Serum for Hair Density; Amazon listing for claims. https://incidecoder.com/products/the-ordinary-multi-peptide-serum-for-hair-density · https://www.amazon.com/dp/B09WMT8HYB (accessed Nov 13, 2026)
8. Katoulis AC, et al. A randomized, single-blinded, vehicle-controlled study of a topical active blend in the treatment of androgenetic alopecia. Dermatol Ther. 2020;33(4):e13734. [Human · n=44 · 24 weeks · Redensyl + Sepicontrol A5 lotion] https://pubmed.ncbi.nlm.nih.gov/32473084/
9. INCIDecoder. Botanic Hearth Rosemary Hair Oil with Biotin, Jojoba and Castor Oils; Amazon listing for claims. https://incidecoder.com/products/botanic-hearth-rosemary-hair-oil-with-biotin-jojoba-and-castor-oils · https://www.amazon.com/dp/B0C6XJMSGP (accessed Nov 13, 2026)
10. US FDA. Cosmetics Labeling Guide (order of ingredient declaration; 21 CFR 701.3). https://www.fda.gov/cosmetics/cosmetics-labeling-regulations/cosmetics-labeling-guide (accessed Nov 13, 2026)
11. eCFR. 21 CFR 701.3, Designation of ingredients. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-G/part-701/subpart-A/section-701.3 (accessed Nov 13, 2026)
12. Scope Grade rubric v1.0. https://formuscope.com/methodology/