Documented concern based on cited evidence — not a personalized safety check, not medical advice, and not a decision to combine or avoid. That decision belongs with your prescriber.
Low-grade concern — timing, disclosure, or lab context
Low-grade documented concern. Timing, disclosure, or a lab context decides whether it matters for you.
Mechanism and evidence
The hair-loss worry traces to one 2009 rugby study where DHT rose during loading, never replicated. The direct 2025 randomized trial in men on 5 g per day for 12 weeks measured hair counts and DHT with no effect on either, and on finasteride the type II conversion pathway the myth depends on is already inhibited.
Evidence tier: rct
The tier names the strongest cited study design. Some anchors studied the supplement on its own, or a related drug in the same class — in those pairs the grade rests on that evidence plus established pharmacology, as agreed with our medical reviewer.
What to discuss with your prescriber
- No documented interaction; the caution grade exists because the combination has been directly tested for hair outcomes and came back clean.
- If creatine is part of your training plan, it does not need to stop on finasteride.