Dutasteride
A more complete DHT blocker than finasteride, with a smaller, though growing, evidence base for hair.
BModerate evidence · often off-label for hair
Dutasteride inhibits both type-I and type-II 5α-reductase, suppressing more DHT than finasteride. Head-to-head trials suggest greater regrowth, but the trial base is smaller and much use is off-label. It is a stronger version of the same brake, with the same structural limit: it does not restart dormant follicles.
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Mechanism & evidence
By hitting both enzyme isoforms, dutasteride drops serum and scalp DHT further than finasteride. Comparative trials, mostly in men, several from single regions, report modestly better hair counts, which earns a B rather than an A: the direction is consistent, the independent replication is still thinner.
Its longer half-life and broader androgen effect also mean a wider side-effect consideration, and it carries the same pregnancy contraindications as finasteride.
Read honestly: a legitimate escalation for men who plateau on finasteride, under medical guidance. Still a defensive move. The complementary, non-hormonal lever, supplying the growth signal, sits with the growth factors.
