The prescription tablet that blocks the hormone behind male pattern hair loss. What it does, how well it works, the side effects regulators have warned about, women, sprays, and what 6 skincare experts said about it on camera.
Finasteride is the hair loss tablet dermatologists name in the same breath as minoxidil, and it rarely comes up without a worried question or two. Does it actually keep your hair? What about the side effects you have read about online? Can women take it? And are the sprays any safer?
Here is where the experts land. They trust it to slow hair loss in men, and the trials back them up. They also talk about it carefully, because it is a prescription medicine with side effects that regulators take seriously. This guide is here to help you have a better conversation with a doctor, not to talk you into it.
Finasteride's Guru Score is 67%. That may look lower than you would expect for a medicine the experts trust to work, and the reason is that the score counts every verdict, the careful ones included. The praise is about results. The reservations are about side effects, especially sexual ones, and about who should never take it. Regulators in the UK, the US and Europe have strengthened their warnings in the last few years, so below, what the experts said sits next to what the studies and the medicine regulators say, and where the two line up.
Finasteride is a prescription medicine that treats male pattern hair loss by blocking the conversion of testosterone into DHT, the hormone that shrinks hair follicles. The experts we track rate it warmly for men, and talk about its side effects with care. The 1 mg tablet is licensed for men only, and must not be used by women who are or may become pregnant [1, 2]. UK and European regulators warn about depression, suicidal thoughts and sexual side effects, which can sometimes continue after stopping [3, 5, 6]. It works only while you take it [2]. Talk to a doctor before starting.
| Question | What we found |
|---|---|
| What is it used for? | Male pattern hair loss (androgenetic alopecia) in men [1, 2]. |
| Do skincare experts recommend it? | Mostly, with care. They trust it to work in men, and take the side effects seriously. |
| Does it need a prescription? | Yes. In the UK it is a private prescription for hair loss, not available on the NHS [16]. |
| How long until it works? | Three months or more of daily use before any benefit shows [1], and three to six months before hair loss steadies [2]. |
| What if you stop? | The gains start to reverse by six months and are back to baseline by 9 to 12 months [2]. |
| Can women use it? | It is not licensed for women, and must not be used in pregnancy or by women who may become pregnant [1, 2, 15]. |
| Main side effect warnings | Sexual side effects, low mood, depression and suicidal thoughts. Sexual problems can sometimes continue after stopping [1, 3, 5]. |
Finasteride blocks an enzyme called 5-alpha reductase, which turns testosterone into a stronger hormone, dihydrotestosterone (DHT). In people prone to pattern hair loss, DHT gradually shrinks the hair follicles on the top of the head, so the hairs grow back thinner and finer [8]. By lowering DHT in the blood and the scalp, finasteride slows that shrinking [8].
It comes in two strengths. The 1 mg tablet (sold as Propecia) is for male pattern hair loss, and a 5 mg tablet (Proscar) treats an enlarged prostate [4]. Dr. Shereene Idriss, a dermatologist, explains that it keeps hairs in their growth phase for longer, and Dr. Daniel Sugai, also a dermatologist, says it suits men thinning at the crown.
It is a prescription medicine in the US and the UK [1, 16]. In the UK, the NHS does not provide it for hair loss, so it comes from a private prescription [16]. Online prescribing makes it easy to get, and the UK medicines regulator has worked with pharmacy and medical bodies because that route can make the recommended monitoring harder [4].
Here is what each of them said on camera, with a link to the moment they said it.
For men Oral Finasteride is very effective. It's a prescription medication but it too has side effects that many men are not interested in. Those side effects are not acceptable. They can have some sexual side effects, so that's not always something people want. Not to mention people are not always so enthusiastic about taking oral medications.Watch ▸
The biggest side effects for both men and women are going to be libido, which can truly really happen, I actually had patients who've complained about this and it is very hard to reverse, so I personally do not give finasteride orally anymore. [...] You can have erectile dysfunction and it could really also even affect women. [...] Finasteride is available topically, and we believe there's going to be much less systemic absorption because it's localized to the area that you're treating.Watch ▸
Finasteride is FDA-approved for male pattern baldness, but it's used off-label in postmenopausal women. It works by blocking the conversion of testosterone to DHT. I don't prescribe it for women of childbearing age because it can cause birth defects, but for postmenopausal patients, it can be definitely a very helpful addition.Watch ▸
Finasteride is a nice oral prescription medication. It works to prevent hair loss in male patients with thinning at the crown and receding hairline. Topical formulations are also available and we do talk about that for male patients and also female patients. [...] That might be a nice option to have like minoxidil compounded with finasteride. I have a few patients over age 60, say 65, or doing very well on that.Watch ▸
90 percent of people saw a 20 percent increase in hair growth. [...] 90 percent show a difference because it's blocking the DHT. That's how this works, that's the pathway of this. [...] You can also do a topical solution of finasteride just like you can do a topical solution of minoxidil.Watch ▸
The experts mostly agree it works in men, so most of the useful detail sits in the caveats.
The evidence in men is strong and long-running. In two one-year trials in 1,553 men aged 18 to 41, 1 mg a day increased hair counts in a patch of the crown by 107 hairs more than placebo at one year and 138 hairs at two years, from a starting count of about 876, while men on placebo kept losing hair [8]. Over five years, the improvement held, while hair loss carried on in the placebo group [9]. In the US label's five-year data, 35% of the men on finasteride had lost hair, against 100% on placebo [1].
A systematic review of 12 trials in 3,927 men found moderate-quality evidence that finasteride raises hair counts and improves how men and their doctors rate their hair, while raising the risk of sexual dysfunction [10]. The US label notes its effect on a receding hairline at the temples has not been established [1].
Darnell Cox, a healthy-ageing creator, says finasteride increases hair growth by 20% in 90% of people. We could not find that figure in the trials or the labels. What the US label reports is that at one year, 14% of men on finasteride had further hair loss, against 58% on placebo, and investigators rated 65% of the finasteride group as having more hair growth [1]. In the systematic review, hair counts rose by about 9% more than placebo in the first year and about 24% more at two years or longer [10]. So it helps most men keep their hair, but the gain varies.
The evidence in women is thin. In a one-year trial in 137 postmenopausal women, 1 mg a day did not increase hair growth or slow thinning compared with placebo [12]. A Cochrane review of female pattern hair loss treatments found finasteride no more effective than placebo, on low-quality evidence, and called for trials of other doses [13]. Dr. Mamina and Dr. Shereene Idriss, both dermatologists, describe using it in women past menopause; that is off-label, and the trial evidence so far does not settle whether it helps.
This is the part the experts and the regulators spend most time on, so here is what the regulators actually say.
In the one-year trials, sexual side effects were uncommon but more frequent than on placebo: lower sex drive in 1.8% against 1.3%, erection problems in 1.3% against 0.7%, and ejaculation problems in 1.2% against 0.7% [1]. In those trials they resolved in men who stopped, and in most who carried on [1]. Since the medicine went on sale, there have also been reports of sexual dysfunction that continued after stopping [1]. Dr. Daniel Sugai says he warns his male patients about rare cases where it could be permanent.
In April 2024 the UK medicines regulator (MHRA) reminded prescribers that finasteride has been associated with depressed mood, depression, suicidal thoughts and sexual dysfunction, and introduced a patient alert card for packs [3]. Prescribers are asked whether you have a history of depression or suicidal thoughts before prescribing, and to monitor you during treatment [3]. In May 2025 the European Medicines Agency confirmed suicidal thoughts as a side effect of finasteride tablets, with a frequency that cannot be estimated from the data [6]. In May 2026 the MHRA strengthened its warnings again: if you develop low mood or suicidal thoughts on finasteride 1 mg, stop taking it and contact a doctor straight away [5]. Both regulators note that sexual problems may contribute to mood changes [5, 6], and the EMA concluded that the benefits still outweigh the risks for the approved uses [6].
Post-finasteride syndrome is the name patient groups use for symptoms, especially sexual problems and depression, that carry on after stopping. The MHRA met the Post Finasteride Syndrome Network during its 2024 review and noted that classifying it as a recognised medical diagnosis is not within its remit [4]. What the regulators do say is that sexual dysfunction may persist after treatment stops [3, 5].
Finasteride lowers PSA, the blood test used to check for prostate cancer, so tell your doctor you take it if you have the test [1]. The US label says this class of medicine may increase the risk of high-grade prostate cancer [1]. The UK label asks men to report any changes in their breast tissue promptly [2].
Several of our experts mention finasteride applied to the scalp, as a spray, solution or a compounded mix with minoxidil. Its regulatory status depends on where you live.
In the US there is no FDA-approved topical finasteride; the products sold are compounded, often through telehealth services, and some mix it with minoxidil [7]. In the EU, finasteride sprays for the skin are authorised in various countries for men aged 18 to 41 with early hair loss [6]. Dr Dray, a dermatologist, points out that it is not an FDA-approved treatment.
In a 24 week European trial in 458 men, a finasteride spray raised hair counts more than placebo (20.2 against 6.7 hairs), with results numerically similar to the tablet [11]. Peak blood levels of finasteride were more than 100 times lower than with the tablet, but blood DHT still fell by 34.5%, against 55.6% on the tablet [11]. Dr Dray makes the same point about the evidence: the trial ran for six months, so long-term results are less certain.
Lower, not zero. Dr. Shereene Idriss prescribes it topically because she expects much less absorption, and still warns that side effects are possible. The EMA found no evidence linking suicidal thoughts to the sprays [6]. The FDA, though, received 32 reports of side effects with compounded topical finasteride between 2019 and 2024, including erection problems, depression and suicidal thoughts, most of which continued after stopping [7]. It also warns that a product applied to the scalp can transfer to other people, which matters for anyone who may be pregnant, and that some patients were told a topical product carried no risk [7].
Only on prescription, and as your prescriber directs. The licensed dose for male pattern hair loss is one 1 mg tablet a day [1, 2].
Tell your doctor if you have ever had depression or suicidal thoughts; the MHRA asks prescribers to check [3]. Read the patient card and leaflet in the pack [5]. A doctor will also want to confirm what kind of hair loss you have, because not every kind responds to a DHT blocker.
The US label says daily use for three months or more is needed before any benefit shows [1], and the UK label says three to six months before hair loss steadies [2]. Keep taking it daily to keep the benefit [2].
Finasteride only works while you take it [15]. If you stop, the benefit starts to reverse by six months and is back to where you started by 9 to 12 months [2]. Stop at once and contact a doctor if you develop low mood or suicidal thoughts [5].
Finasteride must not be used by women who are or may become pregnant, because it blocks a hormone a male baby needs to develop normally [1]. Women who are or may be pregnant should not handle crushed or broken tablets [1, 2]. The NHS says only very small amounts reach semen, and most experts agree a condom is not needed for that reason, although manufacturers recommend one [17]. The NHS says women should not use finasteride for hair loss [15], and that a specialist may prescribe it only in very rare cases [16]. Dr. Mamina says she does not prescribe it to women who could become pregnant.
Finasteride is often one part of a hair loss plan rather than the whole of it.
This is the classic pairing. A meta-analysis of five trials found the combination did better on photo assessments than either medicine alone, with no more side effects [14]. Dr. Shereene Idriss uses topical finasteride as an add-on to minoxidil, and Dr. Daniel Sugai has older patients doing well on a compounded mix of the two. Our minoxidil guide covers the other half.
Yes, for male pattern hair loss in men. In trials in 1,553 men, 1 mg a day raised hair counts on the crown by 107 hairs more than placebo at one year and 138 at two years, while men on placebo kept losing hair [8]. The gains held over five years [9]. The experts we track rate it warmly for men, and the evidence in women is much weaker [12, 13].
Usually three to six months. The US label says daily use for three months or more is needed before any benefit shows [1], and the UK label says three to six months before hair loss steadies [2]. In the trials, the improvement kept building into the second year [8]. Keep taking it daily, because the benefit depends on continued use [2].
The hair loss comes back. The UK label says the benefit starts to reverse by six months after stopping and returns to baseline by 9 to 12 months [2]. The NHS says hair loss treatments only work for as long as you use them [15]. If you want to stop, talk to your prescriber, unless you have low mood or suicidal thoughts, in which case stop and contact a doctor at once [5].
The best known are sexual: lower sex drive, erection problems and ejaculation problems, each in under 2% of men in the one-year trials, slightly more than on placebo [1]. Regulators also warn about low mood, depression and suicidal thoughts [3, 6]. Sexual problems have been reported to continue after stopping in some men [1, 3]. It also lowers PSA test results, so tell your doctor you take it [1].
In April 2024 the MHRA reminded prescribers that finasteride has been linked to depression, suicidal thoughts and sexual dysfunction that can persist after stopping, and added a patient alert card to packs [3]. Prescribers should ask about any history of depression or suicidal thoughts [3]. In May 2026 it strengthened the warnings: stop finasteride 1 mg and contact a doctor straight away if you develop low mood or suicidal thoughts [5].
It is the name patient groups give to symptoms, especially sexual problems and depression, that carry on after stopping finasteride. The MHRA met the Post Finasteride Syndrome Network in its 2024 review and said classifying it as a medical diagnosis is not within its remit [4]. The regulators do say sexual dysfunction may persist after stopping [3, 5], and the US label lists such reports [1]. If you are worried, talk to your doctor.
It is not licensed for women, and the NHS says women should not use it for hair loss [2, 15]. Women who are or may become pregnant must not take it [1]. Some dermatologists, including Dr. Mamina, use it off-label in women past menopause, but a trial of 1 mg in postmenopausal women found no benefit over placebo [12], and a Cochrane review rated the evidence low quality [13]. Ask a specialist.
No. Finasteride must not be used by women who are or may become pregnant, because it blocks a hormone a male baby needs for normal genital development [1]. Women who are or may be pregnant should not handle crushed or broken tablets [1, 2]. The NHS says only very small amounts reach a man's semen, and most experts agree a condom is not necessary for that reason [17].
It reaches the blood far less, but it is not risk-free. In a 24 week trial, peak blood levels were more than 100 times lower than with the tablet, yet blood DHT still fell by about a third [11]. The FDA has had reports of sexual and mood side effects with compounded topical products, and warns it can transfer to others [7]. The EMA found no evidence linking the sprays to suicidal thoughts [6].
It depends where you are. In the US there is no FDA-approved topical finasteride, so products sold there are compounded [7]. In the EU, finasteride sprays are authorised in various countries for men aged 18 to 41 with early hair loss [6]. Dr Dray notes that the topical is not an FDA-approved treatment. Ask a doctor or pharmacist what is licensed where you live.
Yes, and it is a common pairing. A meta-analysis of five trials found the combination did better on photo assessments than either medicine alone, with no rise in side effects [14]. Dr. Shereene Idriss uses topical finasteride as an add-on to minoxidil, and Dr. Daniel Sugai has patients on a compounded mix of the two. Our minoxidil guide covers the minoxidil side.
The evidence is best for the crown. The landmark trials measured hair counts on the top of the head [8], and the US label says its effect on a receding hairline at the temples has not been established [1]. A dermatologist is the person to ask about your own pattern of thinning.
Not for hair loss. The NHS says finasteride is prescription only, and that for hair loss you can only get it on a private prescription and pay the full cost [16]. The MHRA has raised concerns that online prescribing can make the recommended monitoring harder [4]. Whoever prescribes it should ask about your mental health first [3].
6 experts, 12 mentions, every one traced to a video you can watch. Sponsored takes are excluded.
This guide combines two kinds of information. The expert consensus comes from 12 mentions of finasteride by 6 skincare experts in their YouTube videos. Each one was read, given a Yay, Mixed or Nay verdict and linked to the moment it was said. Sponsored takes are excluded. The research sections summarise published studies, medicine labels and regulators' safety notices, listed in full above.
The Guru Score measures how warmly the experts talk about finasteride. It is not a measure of clinical effectiveness, and this guide is not medical advice. Finasteride is a prescription medicine, so talk to a doctor before you start or stop it. It has not been reviewed by a doctor.
This guide is general information, not medical advice. The Guru Score reflects how warmly the experts we track talk about finasteride; it is not a measure of clinical efficacy. Speak to a dermatologist or doctor about a diagnosed skin condition, and before using any medicine.
