Finasteride Vs Dutasteride: How They Compare For Hair Loss
Last reviewed on 24 September 2026. We review our treatment guides every six months to keep them accurate.
Key points
They are the same type of medicine. Finasteride and dutasteride are both 5-alpha-reductase inhibitors, daily tablets that lower DHT, the hormone that drives male pattern hair loss. They treat the underlying cause rather than just stimulating growth.
Dutasteride is the more powerful of the two. It blocks both forms of the enzyme, cutting DHT by around 92 per cent against about 73 per cent for finasteride, and in a head-to-head analysis it was significantly more effective for hair density.
But finasteride is the licensed, first-line choice in the UK. Finasteride 1mg is licensed for male pattern hair loss and is far more widely used and studied; dutasteride is not licensed for hair loss in the UK and is used off-label, usually when finasteride has not done enough.
Their side effects are broadly similar. Both can cause sexual side effects in a small proportion of men, and both must be avoided by women who are or could become pregnant. Dutasteride stays in the body much longer than finasteride.
You take one, not both. Because they work the same way, there is no real benefit to combining them; the usual approach is finasteride first, and dutasteride as a step up if needed.
Neither is a cure. Both work only while you take them, and the benefit fades if you stop. For hair that has already been lost, a transplant is a separate option.
Which suits you is a medical decision. A doctor weighs dutasteride’s extra strength against its off-label status, your response to finasteride, and your circumstances.
Finasteride and dutasteride are the two prescription tablets that tackle male pattern hair loss at its source, by lowering the hormone that shrinks the follicles. They are closely related, which is why people so often ask which is better. The honest answer is that dutasteride is somewhat more powerful, but finasteride is the first-line, licensed choice, and the right one depends on your situation rather than a simple ranking.
This guide compares finasteride and dutasteride neutrally: what each is, how they work, which is more effective, their side effects and licensing, who each suits, and whether they can be combined. It is general information and not a substitute for advice from a doctor.
The short answer
Finasteride and dutasteride do the same job in the same way: they both lower DHT to slow, hold and partly reverse genetic hair loss. The difference is one of degree and status. Dutasteride blocks the DHT-making enzyme more completely, so it is a little more effective, but it is not licensed for hair loss in the UK and is generally used as a second step when finasteride has not achieved enough. So the real question is usually not which is better in the abstract, but whether the extra strength of dutasteride is worth its off-label use for you, which is a decision for a doctor.
What is finasteride, and how does it work?
Finasteride is a once-daily tablet for male pattern hair loss. Genetic hair loss is driven by dihydrotestosterone (DHT), which gradually shrinks sensitive follicles. As a review of these medicines explains, the enzyme finasteride blocks "converts testosterone to dihydrotestosterone (DHT), which amplifies androgen effects in certain tissues", and inhibiting it produces "a substantial reduction in serum (around 70 per cent)" DHT. With less DHT reaching the follicles, the miniaturisation slows and, in many men, partly reverses. The same review notes "long-term use of finasteride at a 1-mg dose proved to be safe and effective in treating male-pattern" hair loss. It works only while taken, and our full guide on finasteride for hair loss covers it in detail.
What is dutasteride, and how does it work?
Dutasteride works in exactly the same way, but more completely. There are two forms of the DHT-making enzyme, type I and type II; finasteride mainly blocks type II, whereas dutasteride blocks both. According to a 2025 network meta-analysis, dutasteride "inhibits both type I and type II 5-alpha-reductase, resulting in a 92 per cent reduction in serum dihydrotestosterone (DHT), compared to a 73 per cent reduction with finasteride". In other words it switches off more of the hormone that causes the loss. It also stays in the body far longer than finasteride, so its effects, and any side effects, clear more slowly after stopping. In the UK it is licensed for an enlarged prostate rather than for hair loss, so its use for hair is off-label; our guide on dutasteride for hair loss explains this.
Which is more effective for hair loss?
On the evidence, dutasteride has the edge. The same network meta-analysis, which pooled the trials of the main treatments, found that "oral dutasteride 0.5 mg/day is significantly more effective than oral finasteride 1 mg/day" for hair density over 24 weeks, and ranked dutasteride "the most effective option" of the medicines it compared. That fits the mechanism: blocking more of the DHT-making enzyme produces a bigger fall in DHT and, on average, a bit more regrowth.
It is worth keeping that in perspective, though. Finasteride is itself an effective, proven treatment that holds or improves hair in the large majority of men who take it, and the extra benefit from dutasteride is a matter of degree rather than a different order of result. For many men, finasteride does all that is needed; dutasteride is the option when it does not.
Finasteride vs dutasteride: how do they compare?
On the measures that matter, the two differ like this:
How they work: both lower DHT by blocking 5-alpha-reductase; finasteride blocks mainly type II, dutasteride blocks type I and II.
Strength: dutasteride cuts DHT by around 92 per cent versus about 73 per cent for finasteride, and is modestly more effective for hair density.
Licensing: finasteride 1mg is licensed for male pattern hair loss in the UK; dutasteride is licensed only for an enlarged prostate, so using it for hair is off-label.
Where each sits: finasteride is the standard first-line tablet; dutasteride is usually a second step when finasteride has not done enough.
How long it lingers: finasteride clears the body within a day or so; dutasteride has a much longer half-life and can stay in the system for weeks to months.
Side effects: broadly similar, mainly a small risk of sexual side effects; both are contraindicated in women who are or may become pregnant. Our guide on finasteride and sexual side effects covers these, and they apply in a similar way to dutasteride.
Evidence base: finasteride has the larger, longer track record; dutasteride is well studied but less so for hair specifically, and not licensed for it here.
Which is right for you?
For most men starting treatment, finasteride is the sensible first choice: it is licensed for hair loss, extensively studied, effective for the majority, and easily reversible. Dutasteride tends to come into the picture when finasteride has been given a fair trial (usually many months) and has not held or improved the hair enough, and the person and their doctor decide the extra potency is worth its off-label use. Some people choose dutasteride from the outset for its greater strength, again as an informed, supervised decision.
Because both are prescription medicines that lower a hormone, the choice, and the monitoring, belongs with a doctor who can weigh the benefits against the side-effect profile and your health, rather than being something to self-select. Neither is suitable in pregnancy or for women who could become pregnant.
Can you take finasteride and dutasteride together?
There is no good reason to. They work by the same mechanism, blocking the same enzyme, so taking both does not add a meaningfully different action, and it would combine their side-effect risks. In practice it is a choice between the two, not a combination: people usually take finasteride, and switch to dutasteride if more is needed, rather than taking them at once. What is commonly combined is a DHT-blocking tablet with a different kind of treatment, such as minoxidil, which stimulates growth by a separate route, so the two cover different angles.
It is also worth remembering that neither tablet can restore hair from follicles that are already gone. Where loss is more advanced, a hair transplant is a separate option that redistributes your own permanent hair, and it is often used alongside a DHT blocker to protect the rest; our guide on hair transplant versus finasteride looks at that comparison.
The bottom line
Finasteride and dutasteride are two versions of the same idea, tablets that lower DHT to treat male pattern hair loss at its source. Dutasteride is the stronger of the two, blocking both forms of the enzyme and cutting DHT by about 92 per cent against roughly 73 per cent for finasteride, and it is modestly more effective. Finasteride, however, is the licensed, first-line, better-studied choice in the UK, while dutasteride is used off-label, usually as a step up when finasteride has not done enough. Both work only while taken, both carry a small risk of sexual side effects, and neither is suitable in pregnancy.
If you are weighing up the two, the sensible step is to discuss them with a doctor, who can judge whether finasteride is enough or whether dutasteride’s extra strength is worth its off-label use for you. And if your hair loss is more advanced than a tablet can address, a proper assessment can set out whether a hair transplant is an option.
Frequently asked questions
Is dutasteride better than finasteride for hair loss?
It is somewhat more powerful. Dutasteride blocks both forms of the DHT-making enzyme and lowers DHT by around 92 per cent, against about 73 per cent for finasteride, and a 2025 network meta-analysis found it significantly more effective for hair density. But finasteride is the licensed, first-line treatment for hair loss in the UK and works well for most men, whereas dutasteride is used off-label. So dutasteride is the stronger option, but not automatically the right one; it depends on your response to finasteride and a doctor’s judgement.
Is dutasteride licensed for hair loss in the UK?
No. In the UK dutasteride is licensed for an enlarged prostate, not for hair loss, so prescribing it for hair is off-label, meaning it is used outside its licensed indication on a doctor’s judgement. Finasteride 1mg, by contrast, is licensed specifically for male pattern hair loss. This is one of the main practical differences between the two, and part of why finasteride is usually tried first.
Can I switch from finasteride to dutasteride?
Many people do, under medical supervision, when finasteride has not held or improved their hair enough after a fair trial of several months. Because dutasteride is more potent, it can help where finasteride has plateaued. It should be a supervised decision, as dutasteride is off-label for hair, has a much longer half-life, and carries a similar side-effect profile. A doctor can advise on whether and how to change.
Do finasteride and dutasteride have the same side effects?
Broadly, yes. Both can cause sexual side effects such as reduced libido in a small proportion of men, and both are contraindicated in women who are or could become pregnant because they can affect the development of a male baby. The main practical difference is that dutasteride stays in the body far longer than finasteride, so any effects clear more slowly after stopping. Anyone concerned about side effects should discuss them with the prescriber rather than stopping suddenly.
Get back to Great Hair
in 3 Easy Steps:
01
Arrange Free Consultation
Speak to one of our specialist consultants for expert advice on our range of different hair loss treatments
02
Book Your Procedure
Place a deposit to reserve a time slot at one of the My Hair UK clinics across the UK
03
Attend Your Surgery
Arrive on the day and our specialist surgical team will look after your every need
What People Say About Us
Read our independent My Hair UK Reviews on Reviews.io
The Surgical Team
The surgical team is what makes the difference on the day. The clinics’ five surgeons are all GMC-registered, with a minimum of 1,000 FUE hair transplant procedures each to their name. Between them the team handles complex cases, including Afro-textured and women’s hair transplants, hairline design and lowering, and revision work.
Manchester clinic
• Dr Khawaja Masood Munir: GMC 6122581.
8+ years’ experience, 1,400+ hair transplant surgeries.
• Dr Haider Gillani: GMC 8030796.
1,000+ procedures, with specific expertise in complex cases requiring detailed anatomical understanding.
London (Harrow) clinic
• Dr Mahdi Alosert: GMC 6168297.
20+ years’ clinical experience. Specialist in Afro-Caribbean hair and hairline lowering.
• Dr Shuaib Mir: GMC 7567898.
1,200+ hair transplant cases. BAAPS plastic surgery and RCS anatomy training.
• Dr Zakar Rafiq: GMC 6164032.
MBBS and BSc (Hons) from Imperial College London. Associate Member of the International Society of Hair Restoration Surgery (ISHRS).
You can meet the surgeon who will perform your procedure at your free consultation.