Melatonin and the Human Hair Follicle.
Study Goal
The researchers sought to evaluate the scientific evidence supporting melatonin's potential benefits for human hair growth, particularly in individuals with alopecia.
Results Summary
The study found that topical melatonin use improved scalp hair growth, density, and hair shaft thickness in subjects with androgenetic alopecia (AGA), with eight out of eleven studies reporting positive outcomes. Effective dosages included 0.0033% or 0.1% topical solutions applied once daily and 1.5 mg oral melatonin taken twice daily.
Population
Subjects with diagnosed alopecia, predominantly men with androgenetic alopecia (AGA).
Effective Dosage
0.0033% or 0.1% topical solution once daily; 1.5 mg oral melatonin twice daily.
Duration
90 to 180 days.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
topical melatonin use | increase | hair health | subjects with androgenetic alopecia (AGA) | - | observed positive outcomes | #1 |
melatonin use | increase | scalp hair growth | melatonin users | - | improved | #2 |
melatonin use | increase | density | melatonin users | - | improved | #3 |
melatonin use | increase | hair shaft thickness | melatonin users | - | improved | #4 |
topical melatonin | increase | hair health | - | 0.0033% or 0.1% solution applied once-daily for 90 to 180 days | effective | #5 |
oral melatonin supplementation | increase | hair health | - | 1.5 mg twice-daily for 180 days | effective | #6 |
melatonin use | increase | scalp hair growth | men with AGA | - | facilitate | #7 |
BACKGROUND: Melatonin, a pleiotropic hormone, affects the physiological processes including that of the hair follicle. We seek to identify the scientific evidence to support the potential benefits of melatonin in human hair growth. OBJECTIVE: To summarize the evidence on the association between melatonin and hair health, denoted by hair growth. METHODS: A literature review using 3 databases (PubMed, Google Scholar, and Cochrane) identified studies investigating the relationship between melatonin and hair loss (2022). The following search terms were used: (hair OR hair loss OR alopecia OR hair growth OR effluvium OR scalp) and (melatonin). Two independent reviewers screened studies for inclusion criteria, and data collection included demographics, melatonin intervention, study type, and effects on hair. RESULTS: A total of 11 human studies were identified with evidence of melatonin use in subjects with diagnosed alopecia (2,267 patients; 1,140M). Eight of the studies reviewed observed positive outcomes after topical melatonin use in subjects with androgenetic alopecia (AGA). Most studies report improved scalp hair growth (n=8), density (n=4), and hair shaft thickness (n=2) among melatonin users compared with controls. Effective topical melatonin dosage appears to be 0.0033% or 0.1% solution applied once-daily for 90 to 180 days vs 1.5 mg twice-daily oral melatonin supplementation for 180 days. CONCLUSION: There is evidence to support melatonin use to facilitate scalp hair growth, particularly in men with AGA. Further studies should include more patients and investigate the mechanism of action. J Drugs Dermatol. 2023;22(3): doi:10.36849/JDD.6921.