Dutasteride for hair loss

What dutasteride is

Dutasteride is a prescription medicine from the same group as finasteride. In the United States and the United Kingdom it comes as a 0.5 mg soft capsule, which is approved for an enlarged prostate, not for hair loss, so taking it for hair there is an off-label use that needs a prescriber. In Japan it is approved for male pattern hair loss. ^{[1, 2, 3]}

Like finasteride, it lowers a hormone called DHT, and the trial reports describe it as doing so more strongly. A bigger drop in a blood hormone is not, on its own, a measure of how much hair comes back or of how many side effects follow. We do not go further here into how it acts on the hair follicle. The sources behind this page are clinical trials, product labels and safety notices from medicines regulators. ^{[4, 5]}

We reviewed one trial of a solution for the scalp. It is research, not a product whose label we could check in the US or UK. ^[4]

This page is about adult men with male pattern hair loss: gradual thinning at the hairline or the crown. If hair is falling out suddenly, in patches, or the scalp is sore or inflamed, the first step is an assessment, not a product. Check that the guide fits your situation before comparing anything.

Where it sits in our comparison

Dutasteride is third in our ranking, in a tier of its own below minoxidil and finasteride. That is not because it works less well: in the large trial that compared the daily capsule with finasteride, it raised hair count more. The position reflects the rest of the decision. It is not approved for hair loss in the US or UK, it stays in the body for months, and the long-term comparison with finasteride is missing. ^{[6, 1, 2]}

How dutasteride rates

Position 3 of 6 in our ranking. The same eight criteria for every ingredient.

Conditional alternative

EffectivenessStrength

Greater total hair-count gain than finasteride in one trialIn a direct trial, the 0.5 mg capsule raised total hair count more than finasteride 1 mg after 24 weeks. The advantage was not shown when only thicker hairs were counted.

Evidence strengthDepends

Limited supportOne large trial against finasteride and placebo, funded by the maker. Longer data come from men who chose to stay on it for five years, with no comparison group.

Risks and tolerabilityTrade-off

Systemic warnings; stays in the body for a long timeSexual side effects were recorded in trials, and the US label says they may continue after stopping. It stays in the body for months, and a precautionary warning about mood was added in the UK in 2026.

TimeDepends

Compared at 24 weeksThe main comparison was measured at 24 weeks. That is when researchers counted, not a promise of a faster result.

CostDepends

Only one local price observedWe found one UK price, at the dose used in the trial, with the consultation fee not included. There is no US price in our check.

RoutineDepends

One capsule a day; long persistence mattersOne capsule a day in the trial. Because it leaves the body slowly, starting or stopping is not a quick experiment.

MaintenanceDepends

Data during use; not established after stoppingFive-year data describe men who kept taking it. What happens to the hair after stopping was not measured in the sources we reviewed.

AccessTrade-off

Hair-loss approval varies by countryThe US and UK labels are for an enlarged prostate, so use for hair loss there is off-label. Japan's label includes male pattern hair loss.

An order of consideration for adult male pattern hair loss, not a score. Strength, Depends and Trade-off describe each line on its own; they do not add up to a number.

The same eight criteria are used for every ingredient in the comparison. How we apply them is on the methodology page.

Capsule or scalp solution

0.5 mg capsule

Conditional

Taken by mouth once a day in the trials. Approved for an enlarged prostate in the US and UK, and for hair loss in Japan.

Evidence in men

917 men over 24 weeks: a larger rise in total hair count than finasteride 1 mg.

Reference use

0.5 mg a day in the trial. Japan's label gives 0.1 mg a day as the usual dose.

Keep in mind

Stays in the body for months. Off-label for hair loss in the US and UK.

Scalp solution

Limited evidence

A 0.05% solution, with one trial that we reviewed. It is research, not a product whose label we could check in the US or UK.

Evidence in men

135 men over 24 weeks: a larger gain than finasteride tablets, in a trial funded by its maker.

Reference use

1 mL once a day on a small test area in the trial. That is not a dose for the whole scalp.

Keep in mind

Some reaches the blood, and the paper's safety reporting does not add up.

Is dutasteride "stronger" than finasteride? On one measure, in one trial, yes: the average rise in total hair count after six months was larger. That is a real result, and it is also narrower than the word suggests. It was not shown for thicker hairs, it says nothing about how any one man will respond, and it was measured at six months, not over years. A larger effect on hair count does not come with a guarantee of the same side effects, or of fewer. ^[6] The page on finasteride against dutasteride takes up this question.

What the trials measured

Against finasteride and placebo

One trial carries most of the weight. It randomly assigned 917 men aged 20 to 50 to five groups: three doses of dutasteride, finasteride 1 mg, or placebo, each taken once a day for 24 weeks. 761 completed it. Hairs were counted inside a circle 2.54 cm across at the crown. ^[6]

• Dutasteride 0.5 mg184 men

  +89.6hairs in the measured area

• Finasteride 1 mg179 men

  +56.5hairs in the measured area

• Placebo181 men

  −4.9hairs in the measured area

Average change in total hair count inside a circle 2.54 cm across. These are hairs in that circle, not hairs per square centimetre and not growth over the whole head. The trial was funded by GSK. ^[6]

The difference between dutasteride 0.5 mg and finasteride was 33 hairs in that circle. When only the thicker "terminal" hairs were counted, the figures were 46.0 against 36.3, and the trial did not show that to be a real difference.

Three limits are worth knowing. The trial lasted six months, which is short for a treatment taken for years. About one man in six did not finish, and their last measurement was carried forward in the analysis. And some of the starting photographs were taken after treatment had begun.

A network analysis of 23 studies, which builds on trials like the one above and is not independent of them, put the gap between the two medicines at about 7 hairs per square centimetre at 24 weeks. Its own authors rated that comparison as low quality, and it had no dutasteride data at 48 weeks. ^[9]

Over five years

The longest data are not a trial. A Korean clinic looked back at 99 men who had taken dutasteride 0.5 mg for at least five years. On photographs, 89 were rated as improved and 93 as not having progressed. ^[10]

That describes men who stayed on the medicine. Anyone who stopped early because it did not work or because of a side effect is not in the 99, and there was no comparison group. We could read only the published summary.

Less often than every day

Because dutasteride leaves the body slowly, some people ask whether it can be taken a few times a week. One small pilot study tested that: 60 men in Thailand, 20 in each group, for 24 weeks. ^[5]

• Dutasteride 0.5 mg, three times a week20 men assigned

  +17.4hairs per cm²

• Finasteride 1 mg, every day20 men assigned

  +12.8hairs per cm²

• Dutasteride 0.5 mg, twice a week20 men assigned

  +7.7hairs per cm²

Change in terminal hair count. Three times a week did better than twice a week. Neither schedule was shown to be better than finasteride. The men knew which schedule they were on, and 58 of the 60 completed the study. ^[5]

The study had no group taking dutasteride every day. So it cannot tell you whether a few capsules a week work as well as one a day, and it cannot show that taking it less often means fewer side effects. It is a first look, not a schedule to follow.

The scalp solution

One trial tested dutasteride as drops for the scalp. It randomly assigned 135 men aged 20 to 60, in six centres in India, to one of three strengths of the solution, to finasteride tablets or to placebo. ^[4]

• Dutasteride 0.05% solution29 men

  +75.5hairs per cm²

• Finasteride 1 mg tablets29 men

  +41.2hairs per cm²

Change in hair count in a 1 cm² area. The trial was funded by the company that makes the solution, all of its authors work there, and the formula is patented. The paper's own totals of men who completed the trial do not fully agree with each other. ^[4]

It is a promising result from a small, short trial of one formula. We found no independent repeat of it in the sources we reviewed, and it does not carry over to another solution with the same percentage on the bottle, to dutasteride injected into the scalp, or to its use with microneedling.

What the evidence does not show

How it is used: what the labels and trials say

There is no hair-loss label for dutasteride in the US or UK. What exists is a prostate label in each of those countries, a hair-loss label in Japan, and the dose used in the trials. We checked the three labels at the end of September 2026. ^{[1, 2, 3]}

Three labels, side by side

US, UK and Japanese capsules, checked at the end of September 2026.

On the label	USAvodart0.5 mg capsules	UKAvodart0.5 mg capsules	JPZagallo0.1 mg and 0.5 mg capsules
Approved for	An enlarged prostate	An enlarged prostate	Male pattern hair loss
Dose	0.5 mg	0.5 mg	0.1 mg, or 0.5 mg if needed
How often	Once a day	Once a day	Once a day
For hair loss	Off-label	Off-label	On the label. Not established under age 20

Each column is one product's own label. The Japanese label was read in translation. A dose approved in one country is not an instruction for another.

The trial against finasteride used 0.5 mg once a day. That describes what was tested. It is not a hair-loss dose approved in the US or UK, and it is not where a person should start without a prescriber. ^[6]

How long it takes

The direct trial counted hair at 24 weeks, and that is the time point we can report for dutasteride against finasteride. It is when the researchers measured, not a promise of when a change shows. The five-year study describes men who were still taking it. ^{[6, 10]}

How long it stays in the body

This is what most sets dutasteride apart from finasteride. Once you have been taking it for a while, half of the medicine is still in the blood about five weeks after the last capsule, and it can be detected for four to six months. Half of a dose of finasteride is gone in five to six hours. ^{[1, 11]}

• DutasterideAfter regular daily use

  About 5 weeks

• FinasterideMen aged 18 to 60

  5 to 6 hours

From the US labels of each medicine. These figures describe the medicine in the blood. They do not describe the hair, and they are not a timetable for a side effect to settle. ^{[1, 11]}

Side effects and safety

As with finasteride, three kinds of information are involved and should not be mixed: what was counted in trials, what regulators warn about, and what is still not known. For dutasteride in hair loss, the third group is the largest. The comparison with finasteride sets the side effects of the two medicines side by side.

Sexual side effects

In the 24-week trial, sexual or breast-related side effects were tracked as a special category. ^[6]

• Dutasteride 0.5 mg19 of 184 men

  10.3%

• Finasteride 1 mg24 of 179 men

  13.4%

• Placebo12 of 181 men

  6.6%

Men with at least one such event. Impotence was recorded in 10, 11 and 7 of them. Groups of this size cannot show that dutasteride is safer than finasteride, or that the two are equally safe. ^[6]

A second trial was built to look at sexual function. It enrolled 117 sexually active men and asked about it directly. Over 24 weeks, sexual side effects were reported by 9 of 58 men on dutasteride and 5 of 59 on placebo. Four were still present when treatment ended, and those cleared within six weeks of the last capsule. The trial was small and funded by the maker, and the impotence reports were concentrated in particular study centres. ^[12]

A pooled analysis of 15 finasteride and dutasteride trials put sexual side effects in its dutasteride 0.5 mg group at about 1.4 times the placebo rate, with a range running from slightly fewer than placebo to more than twice as many. A range that wide does not show that there is no risk, and it cannot be set against the figure for finasteride to say which is safer. ^[13]

Effects that continue after stopping

The US label says that sexual side effects may continue after dutasteride is stopped, and that the role of the medicine in this is not known. There is no reliable figure for how often it happens. The trial in which side effects cleared within six weeks describes those men. It does not rule out longer-lasting problems in others. ^{[1, 12]}

Mood

In May 2026 the UK regulator added a warning about changes in mood to dutasteride capsules. It is a precaution based on the group of medicines dutasteride belongs to and on very limited data for dutasteride itself. It is not the same conclusion the regulator reached for finasteride, where depression and suicidal thoughts are confirmed side effects. The European review of 2025 likewise did not establish a link for dutasteride. ^{[7, 14]}

Fertility, pregnancy and blood tests

Semen. The US label reports a study in healthy men aged 18 to 52: 27 took dutasteride 0.5 mg and 23 took placebo for a year. ^[1]

• Semen volume

  26%

• Total sperm count

  23%

• Sperm motility

  18%

27 men on dutasteride and 23 on placebo. Twenty-four weeks after stopping, the average sperm count in the dutasteride group was still 23% below where it started. Two men had falls of more than 90%, with partial recovery. ^[1]

These are averages in a small group of healthy volunteers. The label says the effect on a man's fertility is not known: the study measured semen, not pregnancies. An average that stays in the normal range also does not rule out a large change in one person.

Pregnancy. The US label warns that dutasteride can be absorbed through the skin from a leaking capsule, and it is not for women or children. If your partner is pregnant or you are trying to conceive, the leaflet for your own product and country is the reference, and it is a question to raise with the prescriber. We do not work out a waiting time from these sources. ^[1]

PSA. Dutasteride lowers PSA, a blood marker used to check the prostate, by about half within three to six months in the prostate trials. Tell the clinician who orders or reads the test that you take it. ^[1]

With the scalp solution

The solution's paper states that no side effects occurred. It also describes changes to the skin and gives a figure for them that does not match the number of men. In the 16 men whose blood was tested, small amounts of dutasteride were measurable in some samples, though most readings were near or below the limit of measurement. A small, short trial with reporting like this cannot support "no risk", and drops on the scalp do not stay only on the scalp. ^[4]

If you stop

What happens to the hair after stopping dutasteride was not measured in the sources we reviewed. The five-year study followed men who continued, and the hair trials stop measuring at 24 weeks. ^{[10, 6]}

Two things are known. The medicine stays in the blood for months after the last capsule. And that is not evidence that the hair benefit stays too.

If you are thinking of stopping because of a side effect, tell your prescriber what you noticed and when. The section on effects that continue after stopping explains what is and is not known.

Combining dutasteride with other options

Dutasteride has far less evidence on combinations than finasteride or minoxidil. ^{[6, 8, 15, 4]} What is known about those two together is on the minoxidil and finasteride page.

• Dutasteride + finasteride

  Alternatives, not a pair

  Both belong to the same group of medicines, and the trials compared one against the other. The UK finasteride label excludes taking it with another medicine of that group. No source we reviewed tests a schedule for switching between them.

  Finasteride and dutasteride compared

• Dutasteride + minoxidil, on the scalp or as tablets

  Not established

  Finasteride has been studied together with minoxidil. For dutasteride we found no result we could verify: the reports we identified could not be read in full or could not be relied on. That is a gap in what we could check. It is not proof that the pairing does not work.

  Full minoxidil profile

• Dutasteride + the capsule and a scalp solution together

  Not established

  They are two routes for the same medicine. The solution trial compared the drops with finasteride tablets, not with dutasteride capsules, and nothing we reviewed tests using both.

• Dutasteride + microneedling or injections into the scalp

  Not covered by the trial

  The solution trial tested drops applied to the skin. It says nothing about dutasteride injected into the scalp or used with microneedling.

  Microneedling for hair loss

For the bigger picture of what goes with what, see which options can be combined and which are alternatives.

What it costs

We recorded one price for dutasteride, in the UK, on 29 September 2026. It is worked out for 30 days at the dose used in the trial. It is an example, not a national average. The finasteride and minoxidil prices from the same check are shown next to it.

United Kingdom · pounds

• Dutasteride 0.5 mg capsulesOnline pharmacy, one capsule a day

  £17.98

• Finasteride 1 mg tabletsOnline pharmacy, generic

  £9.46

• Minoxidil 5% solutionOnline pharmacy, 1 mL twice a day

  £16.25

• Minoxidil 5% foamRegaine for Men, 1 g twice a day

  £19.17

Medicine only. The dutasteride price is £17.98 for 30 capsules. It requires a consultation, and that fee and delivery are not included because we could not confirm them. Use for hair loss is off-label in the UK.

Over a year the capsules come to about £219 in this example. We did not record a US price, and we found no price for a scalp solution that matches the one tested. Price says nothing about which works better.

Not for women or under-18s

The US label is not for women or children, and it warns about contact with leaking capsules. The Japanese hair-loss label does not establish that dutasteride works or is safe under the age of 20. This page and our hair guide are written for adult men, and nothing here should be carried over to hair loss in women. ^{[1, 3]}

Keeping track

Day-to-day changes are too small to see in the mirror. Three habits help. They are organising suggestions of ours, not something tested in a trial:

Bring all three to the review with your prescriber. With a medicine that leaves the body this slowly, noticing a change early and saying so matters more than usual.