Comparison of Once‐Daily Versus Twice‐Daily 0.5% Finasteride Solution in Men With Androgenetic Alopecia: A Randomized, Assessor‐Blinded Clinical Trial
Chantaluck Muennarong, Pintusorn Kungvalpivat, Salinee Rojhirunsakool, Saranya KhunkhetBackground
Topical finasteride has been alternatively used to treat male androgenetic alopecia, with studies indicating that once‐daily topical finasteride is not only effective but may be superior to twice‐daily application in suppressing scalp dihydrotestosterone levels. However, comparative data on hair regrowth between once‐daily and twice‐daily dosing are still lacking.
Objective
To compare the application frequency of topical finasteride and its clinical outcomes.
Methods
This randomized, assessor‐blinded clinical trial involved 60 men with androgenetic alopecia. Participants were randomly allocated to receive a 0.5% finasteride solution once or twice daily for 24 weeks. Main outcome measures included changes in hair density and diameter, global photographic assessment, and adverse events.
Results
Forty‐eight men completed the study. Intention‐to‐treat and complete‐case analyses produced consistent findings. At 24 weeks, both once‐daily and twice‐daily applications resulted in significant improvements in total hair counts, terminal hair counts, and hair diameter from baseline (all p < 0.001). Twice‐daily dosing was significantly superior to once‐daily dosing for increasing total hair density, +29.7 versus +20.7 hairs/cm 2 ( p = 0.002), whereas increases in terminal hair counts and hair diameter were similar between groups. Twice‐daily dosing was associated with a higher rate of significant hair regrowth, 61% versus 40% ( p = 0.149). However, higher incidences of mild local reactions were also observed with twice‐daily dosing, 17% versus 7% ( p = 0.427).
Conclusion
Both once‐daily and twice‐daily regimens of topical finasteride 0.5% for 24 weeks were effective and well‐tolerated in men with androgenetic alopecia. Twice‐daily application provides additional clinical benefits compared to once‐daily use.
Trial Registration: Thai Clinical Trials Registry (TCTR): TCTR20240816002