Dutasteride vs finasteride: is the stronger one worth it?
Updated
Dutasteride comes up as soon as you read past the basics. It works like finasteride, only stronger. Stronger sounds better, but it comes with trade-offs worth understanding before you ask for it.
This is general education. A dermatologist should make this call with you.
How they differ
Both drugs block 5-alpha reductase, the enzyme that turns testosterone into DHT, the hormone behind pattern hair loss. There are two types of this enzyme. Finasteride blocks one; dutasteride blocks both, so it lowers DHT further.
- Approval: finasteride 1 mg is FDA-approved for hair loss. Dutasteride is approved for hair loss in South Korea and Japan, and in the US only for an enlarged prostate, so for hair it is prescribed off-label.
- Dose for hair: finasteride 1 mg a day; dutasteride usually 0.5 mg a day.
- How long it stays in you: finasteride clears in days. Dutasteride takes months to leave the body after you stop.
- Cheapest legit price: both are inexpensive as generics, roughly $5–$10 a month for finasteride and $10–$20 for dutasteride, plus a prescription visit.
Does dutasteride work better?
In a large randomized trial, 0.5 mg dutasteride produced more new hair than 1 mg finasteride after 24 weeks, and an earlier dose-ranging trial found the same direction. So on hair count, yes, it tends to do more.
The catch is that finasteride has far more long-term hair loss data, decades of it. For most men starting out, finasteride is still the first step, with dutasteride kept for men who keep losing hair on it.
Side effects and what is different
- Similar kinds of side effects: lower libido, erectile issues, and less ejaculate, possibly slightly more often than with finasteride.
- They last longer if they happen. Because dutasteride lingers for months, side effects can take longer to fade after stopping.
- PSA: like finasteride, it roughly halves PSA, a prostate cancer screening test. Tell any doctor who orders one.
- Blood donation: do not donate blood until 6 months after your last dose.
- Pregnancy: women who are or may be pregnant should not handle the capsules.
Read more about this family of drugs in finasteride side effects.
Who should consider it
- You have been on finasteride consistently for about a year, with photos, and are still losing hair.
- You tolerated finasteride without side effects.
- You have talked it through with a dermatologist who is comfortable prescribing it off-label.
If you are just starting out, begin with finasteride, minoxidil, or both. See finasteride vs minoxidil.
Common questions
Is dutasteride better than finasteride for hair loss?
It lowers DHT more and grew more hair than finasteride in a head-to-head trial. It also has less long-term hair loss data, is off-label in the US, and stays in the body for months, so most men start with finasteride.
Can I switch from finasteride to dutasteride?
Many men do, under a dermatologist's care, usually after about a year of finasteride without enough results. Do not combine them on your own.
Is dutasteride FDA-approved for hair loss?
No. In the US it is approved for an enlarged prostate and prescribed off-label for hair loss. It is approved for male hair loss in South Korea and Japan.
Sources
- Gubelin Harcha et al., 2014, J Am Acad Dermatol: dutasteride vs finasteride in men with androgenetic alopecia
- Olsen et al., 2006, J Am Acad Dermatol: dutasteride dose-ranging study
- FDA Avodart (dutasteride) prescribing information
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