Melatonin and hair loss: what the latest studies show

This isn’t wishful thinking, either. A systematic review published in 2023 in the Journal of Drugs in Dermatology pulled together 11 clinical studies involving more than 2,267 patients. Of those, 8 reported positive effects on hair regrowth.

So is this a genuine therapeutic avenue or just another overhyped ingredient? The data deserves a proper look. First, though, a quick bit of biology.

A hormone your hair follicles make on their own

Put the sleeping tablets out of your mind for a second. Melatonin is, above all, a powerful antioxidant, one that can mop up free radicals responsible for speeding up cellular ageing. It also has a hand in regulating inflammation and immune responses. Quite the CV for a single molecule.

What really got researchers curious, though, was something nobody quite expected. Your hair follicles don’t simply soak up melatonin from the bloodstream. They manufacture it themselves.

Work published in the FASEB Journal confirmed as much: during the anagen phase (the active growth stage), follicles synthesise their own melatonin and express functional receptors. The MT1 receptor, specifically, has been identified in dermal papilla cells, that tiny structure sitting at the base of the follicle that essentially runs the show when it comes to hair growth.

Mice bred without the nuclear receptor RORα (another receptor responsive to melatonin) grow noticeably thinner fur, which adds another piece to the picture.

Melatonin isn’t just passing through the follicle, then. It’s built into the system. And when levels fall, the hair growth cycle feels the effects.

What the clinical trials actually found

40 women, a world first

Dr Tobias Fischer’s team kicked things off in 2004 with a double-blind, placebo-controlled trial. 40 women with androgenetic alopecia (alopecia areata) or diffuse alopecia applied a 0.1% melatonin solution to their scalp nightly for six months.

The team found a significant increase in anagen-phase hairs in the occipital region (P=0.012). On the safety front, melatonin absorbed through the skin stayed within normal night-time physiological ranges. No hormonal disruption was reported.

41% increase in density in men

A separate trial involving 35 men with androgenetic alopecia went further, using TrichoScan, a digital imaging method for the scalp. With an even more diluted solution (0.0033%) applied daily over six months, density rose from 123 hairs/cm² to 173/cm². That works out at +41% (P<0.001). More than half the men were already seeing clear improvements by month three.

1,800 volunteers, 200 centres

The biggest study enrolled over 1,800 volunteers across 200 centres. After just three months of treatment, the proportion of patients with a positive traction test (indicating active shedding) dropped from 61.6% to 7.8%.

Meanwhile, those with a negative test climbed from 12.2% to 61.5%. The researchers also picked up improvements in seborrhoea and dandruff, something nobody had been looking for.

The 2023 review

The most recent review (Gupta et al.) backs up these earlier findings. 8 out of 11 studies show measurable benefits across hair growth (8 studies), density (4 studies), and thickness (2 studies). The dosages used most often sit at around 0.0033% or 0.1%, applied once daily for three to six months.

How melatonin works at the follicle level

Scientists haven’t cracked every detail yet, but several mechanisms are becoming clearer.

An antioxidant shield. Active follicles are among the most metabolically demanding structures in the body. All that energy consumption throws off free radicals which, over time, damage dermal papilla cells. Melatonin scavenges these harmful molecules and ramps up defence enzymes like superoxide dismutase. The upshot: follicles stay healthier for longer.

A brake on miniaturisation. Newer research suggests melatonin can push androgen receptors out of the cell nucleus, dialling down their activity. Since DHT (dihydrotestosterone) is the hormone that gradually shrinks follicles in androgenetic alopecia, this is significant. It would work alongside finasteride, which blocks DHT production further upstream.

A stronger growth signal. A study in PeerJ showed melatonin activates the Wnt/β-catenin pathway in dermal papilla cells, boosting their size by 12 to 21%. This molecular cascade plays a direct role in triggering the anagen phase.

These mechanisms all point the same way: keeping follicles in their active growth phase for longer by slowing cell death and influencing hormone receptors. That’s particularly relevant for women dealing with hair loss, where diffuse alopecia is common and still frequently goes undiagnosed.

What to keep in mind

Promising as these numbers are, topical melatonin isn’t a miracle treatment, not yet, at least. There are real caveats.

Most of the studies are open-label, with no placebo group. Only Fischer’s 2004 trial ticks every box for a rigorous scientific protocol. The rest can’t fully account for seasonal fluctuations in hair growth, a well-known bias in trichology that can easily distort results.

There’s also the issue of formulation. Many of the tested products combine melatonin with ingredients like ginkgo biloba or biotin, making it tricky to tease apart what melatonin alone is doing versus these other compounds, which have their own recognised hair-health properties.

Results vary by scalp region, too. In women with androgenetic alopecia, benefits showed up at the back of the head but not along the frontal hairline, where androgen receptors are more densely packed.

As things stand, topical melatonin sits best as a complement, not a replacement, for minoxidil or finasteride, both of which have far more robust evidence behind them. It can slot into a broader treatment plan for early-stage alopecia, but on its own, it won’t reverse established baldness.

When topical treatments reach their limits

Once hair loss has progressed to the point where thinning is clearly visible and the scalp is showing through, creams and solutions can only do so much. That’s where hair transplant in Turkey comes in.

Dr Emrah Cinik has been helping patients through this journey for over 20 years, using techniques matched to each person’s needs.

The Sapphire FUE hair transplant relies on sapphire-tipped blades for ultra-fine incisions, quicker healing, and results that look natural. When precision placement matters most, the DHI technique with a Choi pen gives the surgeon millimetre-level control over the angle, direction, and depth of every single graft.

Every procedure includes PRP (Platelet-Rich Plasma) sessions as standard. PRP delivers growth factors straight to the follicles, supporting graft survival and encouraging regrowth.

In many ways, this approach mirrors what melatonin research is trying to achieve: protect existing follicles and give them the best possible conditions to produce healthy hair.

Want to find out more? A free consultation with Dr Cinik’s team gives you an accurate diagnosis and a personalised treatment plan.

Scientific references

Fischer, T. W., Slominski, A., Tobin, D. J., & Paus, R. (2008). Melatonin and the hair follicle. Journal of Pineal Research, 44(1), 1-15. https://pubmed.ncbi.nlm.nih.gov/18078443/

Fischer, T. W., Burmeister, G., Schmidt, H. W., & Elsner, P. (2004). Melatonin increases anagen hair rate in women with androgenetic alopecia or diffuse alopecia: results of a pilot randomized controlled trial. British Journal of Dermatology, 150(2), 341-345. https://pubmed.ncbi.nlm.nih.gov/14996107/

Fischer, T. W., Trüeb, R. M., Hänggi, G., Innocenti, M., & Elsner, P. (2012). Topical melatonin for treatment of androgenetic alopecia. International Journal of Trichology, 4(4), 236-245. https://pmc.ncbi.nlm.nih.gov/articles/PMC3681103/

Gupta, A. K., Venkataraman, M., Talukder, M., & Bamimore, M. A. (2023). Melatonin and the Human Hair Follicle. Journal of Drugs in Dermatology, 22(3). https://pubmed.ncbi.nlm.nih.gov/36877877/

Cho, Y. H., Jeon, Y. H., & Hong, S. H. (2022). Melatonin increases growth properties in human dermal papilla spheroids by activating AKT/GSK3β/β-Catenin signaling pathway. PeerJ, 10, e13461. https://pmc.ncbi.nlm.nih.gov/articles/PMC9123888/

Ferrara, F., Ferrara, G., & Ferrara, P. (2024). Clinical Studies Using Topical Melatonin. International Journal of Molecular Sciences, 25(9), 5167. https://pmc.ncbi.nlm.nih.gov/articles/PMC11121188/

Ho, C. H., Sood, T., & Zito, P. M. (2023). Androgenetic Alopecia: An Update on Pathogenesis and Pharmacological Treatment. Clinical, Cosmetic and Investigational Dermatology, 18, 1495-1520. https://pmc.ncbi.nlm.nih.gov/articles/PMC12380480/

Adil, A., & Godwin, M. (2022). Treatment options for androgenetic alopecia: Efficacy, side effects, compliance, financial considerations, and ethics. Journal of Dermatological Treatment, 33(4), 1837-1845. https://pmc.ncbi.nlm.nih.gov/articles/PMC9298335/