Dutasteride
Also known as Avodart
A more complete DHT blocker than finasteride. More potent, longer half-life, and correspondingly less forgiving.
Generic dutasteride roughly $20–50/month depending on source.
How it works
Inhibits both type I and type II 5-alpha-reductase, suppressing serum DHT by over 90% compared with roughly 70% for finasteride. Its half-life is measured in weeks rather than hours.
How it's used
Typically 0.5mg daily or several times weekly, off-label for hair loss in most countries and prescribed after finasteride proves insufficient. Requires a prescriber who will actually monitor you.
Trade-offs
In favour
- Greater DHT suppression than finasteride
- Head-to-head trials show superior hair count outcomes
- An option for finasteride non-responders
Against
- Off-label for alopecia in most jurisdictions
- Very long half-life — side effects take months to clear
- Same side-effect profile as finasteride, potentially at higher incidence
- Harder to obtain
Risks and side effects
- Sexual side effects, potentially more frequent than finasteride
- Extended washout — effects persist for months after stopping
- Not for women of childbearing potential
- PSA suppression
How good is the evidence?
Good randomised evidence including head-to-head comparison with finasteride, though approved for hair loss in fewer countries.
Sources
Sources point to guideline bodies and literature searches rather than single papers, so they stay accurate as the evidence moves.