Topical Finasteride Spray for Male Pattern Hair Loss: Phase III Trial Research Summary
This is a plain-language summary of the original published research. We do not add conclusions or opinions of our own. This is not medical advice — consult a certified healthcare practitioner before making any decision.
Original research published in British Journal of Dermatology, 2022
Topical Finasteride Spray for Male Pattern Hair Loss: Phase III Trial Research Summary
Study conclusion
Topical finasteride is not FDA-approved. The FDA issued an adverse event communication in 2024 for compounded topical finasteride. This Phase III trial found that a topical finasteride spray significantly increased hair count compared to placebo in men with pattern hair loss. The effect was similar in size to oral finasteride, but topical application resulted in much lower absorption of finasteride into the bloodstream.
Strength of evidence
Who it applies to
Who was studied
Men with pattern hair loss. 458 participants across 45 European clinical sites. 24-week treatment period.
Who was NOT studied
Women with pattern hair loss. Men with very advanced hair loss. People outside the trial population characteristics.
What to look for when shopping
Topical finasteride is not FDA-approved. All topical finasteride products in the US are compounded (custom-made by pharmacies) and prescribed off-label. The FDA issued an adverse event communication about compounded topical finasteride in 2024.
What research cannot help you decide
Whether topical finasteride is safe for long-term use — this trial ran only 24 weeks. Whether the lower systemic absorption makes it meaningfully safer than oral finasteride for you specifically. These are questions for a prescribing doctor.
Key findings
- Topical finasteride spray significantly increased hair count at the scalp vertex compared to placebo (about 20 more hairs in the target area at week 24)
- The effect was similar in size to oral finasteride in this trial
- Topical application resulted in much lower suppression of DHT throughout the body compared to oral finasteride
- The hair count improvement was visible from week 12
- Topical finasteride is NOT FDA-approved — all US products are compounded and off-label
What this study does not show
- 1.Whether topical finasteride is safe long-term. This trial ran only 24 weeks.
- 2.Whether reduced systemic DHT suppression meaningfully reduces sexual side effects. The trial was not powered to detect differences in sexual dysfunction rates.
- 3.How topical finasteride performs in women. This trial studied men only.
- 4.Whether compounded topical finasteride products available in the US perform the same as the study formulation.
Limitations
- 1.Industry-funded trial (Almirall). Industry funding introduces potential for positive result bias.
- 2.24-week trial only. Long-term efficacy and safety are unknown.
- 3.Conducted in Europe. Regulatory and compounding standards for topical finasteride differ in the US.
- 4.Topical finasteride is not FDA-approved. The FDA issued an adverse event communication for compounded topical finasteride products in 2024.
Used in these articles
Links added as fact-checks and articles citing this study are published.