What is Propecia? Uses, benefits and risks
Thinking about Propecia for hair loss? How it works, who takes it, its side effects, and what you can do if you get them.

Propecia is the brand name for finasteride 1 mg, a daily tablet for male pattern hair loss. It can slow hair loss, and its UK leaflet lists sexual problems that persist after stopping, which patients call post-finasteride syndrome (PFS).
Most people who look up Propecia are deciding whether to take it. The leaflet answers more of that question than the adverts do.
Sam took finasteride to stop his hair falling out. Watch from 3:56 to hear what he was told before he started.
His GP pointed him to the NHS website, where he read that erection problems might happen. Was anything said about them lasting? “Nothing permanent,” he says.
So what does Propecia do, and what should you know before you start?
How does Propecia work, and who takes it?
Propecia blocks an enzyme called 5-alpha reductase. That enzyme turns testosterone into a stronger hormone, DHT.
In men with this kind of hair loss, DHT slowly shrinks hair follicles on the scalp. The official prescribing information says finasteride lowers DHT in the scalp and in the blood.
Finasteride was first sold at 5 mg, as Proscar, for an enlarged prostate. Propecia is the same medicine at a fifth of that dose. Our page on finasteride 5 mg covers the prostate tablet.
For many men it slows hair loss, and some regrow a little. The leaflet says it “may take 3 to 6 months for the full effect to develop”.
The benefit lasts only while you take it. “If you stop taking Propecia, you are likely to lose the hair you have gained within 9 to 12 months,” the leaflet says. So it is a tablet you take every day for years.
Propecia is for men. The leaflet says not to take it if you are a woman, and that it “should not be used in children”.
It is not prescribed on the NHS for hair loss, so people get it privately. Many order it from online pharmacies after filling in a short form.
Robb Dixon, who has PFS, told ITV’s Good Morning Britain about ordering it that way. The form took “30 seconds probably”, he said.
Our page on buying Propecia online looks at what those services tell you.
What are the side effects of Propecia?
The best known are lower sex drive and erection problems. In the trials behind the label, lower sex drive was reported by about 2 in 100 men on finasteride, against about 1 in 100 on a dummy tablet.
The leaflet also lists:
- Mood: depressed mood, depression, anxiety and, less often, suicidal thoughts.
- Sex: problems with ejaculation, and sexual problems without any change in mood.
- Breasts: swelling or tenderness. Report lumps, pain or nipple discharge to your doctor.
- Fertility: male infertility and poor quality of semen.
If your mood drops, the leaflet says to stop taking Propecia and contact your doctor as soon as possible. If you’re struggling, the Samaritans are free to call on 116 123, day or night.
Can Propecia side effects last after stopping?
Yes, for some people. The leaflet lists “persistent difficulty having an erection after discontinuation of treatment”, and lasting problems with sex drive and ejaculation too.
Nobody has measured how often this happens. The leaflet puts these under “Frequency unknown”. For some people it has lasted years after stopping. Nobody knows yet who will be affected, or whether it will ease.
People with PFS describe more than sex. They talk about numbness, brain fog and feeling flat. Our list of PFS symptoms and patient stories show what that looks like day to day.
The criteria proposed in 2022 say cognitive problems, depression and suicidal thoughts can come with the sexual problems, or happen without any sexual difficulties.
What can you do if you have side effects?
Propecia helps many men keep their hair. If you have side effects, that’s a decision for you and your prescriber. Follow what the leaflet says about mood changes.
Many people say it took time to be taken seriously. Bring the leaflet line to your appointment. You can report it without a doctor agreeing.
Questions to take to your GP
Start with: "I have problems that began on Propecia or after I stopped."
1. Your dates: "Propecia 1 mg from January 2023, last tablet March 2024."
2. What changed, in your words: "Touch feels numb", "I can't think clearly", "I feel flat".
3. Could anything else explain this?
4. Can you report this as a Yellow Card, or note it in my record?
Report it: it helps everyone
A doctor’s note helps you. A report to the medicines regulator helps everyone else: it is how patterns get noticed.
- No proof needed. A suspicion is enough, even years after stopping.
- Where: the Yellow Card scheme in the UK, MedWatch in the US.
- Use the right words. If symptoms continued after stopping, write Post 5-alpha-reductase inhibitor syndrome (MedDRA 10082430).
Our reporting guide walks you through it
Frequently asked questions
Is Propecia the same as finasteride? Yes. Propecia is a brand of finasteride 1 mg. Generic finasteride 1 mg tablets contain the same medicine and carry the same warnings.
Is Propecia safe? It is licensed in the UK, and many men take it without problems. Its leaflet lists depression, suicidal thoughts and sexual problems that persist after stopping. Our page on whether finasteride is safe goes further.
What happens when you stop Propecia? Hair gained is usually lost within a year, the leaflet says. Some side effects ease, and for some people they don’t. Our page on stopping finasteride has more.
Sam was warned about erection problems, but “nothing permanent”. If yours have lasted, read about post-finasteride syndrome and report it.
Sources
- Propecia 1 mg film-coated tablets: patient information leaflet, last revised May 2026, electronic medicines compendium (emc). Section 1 (use), section 2 (women, children, mood), section 3 (3 to 6 months; hair lost within 9 to 12 months of stopping), section 4 (lasting erection, sex drive and ejaculation problems under “Frequency unknown”).
- Propecia 1 mg: summary of product characteristics, emc. Section 4.8: decreased libido 1.8% against 1.3% on placebo at month 12. Section 5.1: mechanism.
- MHRA, Finasteride and dutasteride: updated safety warnings for psychiatric side effects and sexual dysfunction, Drug Safety Update, 11 May 2026.
- Healy D, Bahrick A, Bak M and colleagues. Diagnostic criteria for enduring sexual dysfunction after treatment with antidepressants, finasteride and isotretinoin. Int J Risk Saf Med 2022;33(1):65-76. Proposed criteria from expert agreement. Section 5: cognitive impairment, depression and suicidality “can occur independently of any sexual difficulties but may also accompany sexual problems”.
- Moral Medicine, The Hidden Devastation of Finasteride – Sam’s Story, June 2025. Warning from 3:56; “nothing permanent” at 4:32.
- Good Morning Britain, ITV, Pharmacists warn against buying prescription drugs online, 11 February 2026. Robb Dixon from 0:49.
Sources checked on 22 October 2026. AI-assisted writing and review, not clinical review.
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Finasteride: what the official texts say, country by country
For the 5α-reductase inhibitor finasteride (Propecia), the product information we read in the United Kingdom, in the United States, in Canada, in Australia, in New Zealand, in Germany, in France, in Italy, in Spain, in Brazil and in India, in some places that of another product, lists sexual dysfunction that continued after treatment was stopped. In each of those texts it stands among side effects reported once the medicine was in general use. Several add that these reports come from a group of unknown size, so how often this happens, and whether finasteride is the cause, cannot always be established. Patients call lasting effects after finasteride post-finasteride syndrome (PFS). The wording a European Commission decision set for the EU in 2025 is about mood and thoughts of suicide, and has no sentence about sexual side effects continuing after the medicine is stopped.
This is a record of what each text says and of the date it prints. A text is quoted in its own words, or summarised where the row says so. It is not a comparison of countries. All medicines and countries
Finasteride: the official texts, country by country (85 texts read)
| Country or region | What the text says | Document | Dates |
|---|---|---|---|
| United Kingdom | Sexual side effects, as listed4.8 Undesirable effects · Psychiatric disorders: · Uncommon*: Sexual side effects, as listed4.8 Undesirable effects · Reproductive system and breast disorders: · Uncommon*: Sexual side effects that continue after stopping4.8 Undesirable effects The same text also says4.8 Undesirable effects Sexual side effects, as listed4.8 Undesirable effects Sexual side effects, as listed4.8 Undesirable effects This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals Summary of Product Characteristics (SmPC): Propecia 1 mg Film-Coated TabletsPropecia 1 mg film-coated tablets, Organon Pharma (UK) Limited · Read in a compendium of product information: emcAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; 5 related documents, with such a sentence; 5 related documents, with no such sentence | Text revisedChecked |
| European Union | This text has no sentence about sexual side effects continuing after the medicine is stopped. This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. This is wording for national product texts. There is no single EU product text for this medicine. | Document from the regulator Finasteride- and dutasteride-containing medicinal products, Article 31 referral: Annex III Amendments to relevant sections of the Product InformationRead on the regulator's site: European Medicines AgencyAlso on record: 2 more related documents, with no such sentence | The text prints no dateChecked |
| United States | Sexual side effects that continue after stopping6 ADVERSE REACTIONS · 6.2 Postmarketing Experience The same text also says6 ADVERSE REACTIONS · 6.2 Postmarketing Experience This sentence stands in the list of adverse reactions. The warnings section of this text has no entry on sexual function. Texts for other products in this country do not all say the same. The ones we read are on the full record. This text names sexual side effects in several places that this row does not show. Together those passages are too long to reproduce here. The document link in this row opens the text. That they are not shown says nothing about how common these side effects are. On 14 October 2026 we searched the labels in openFDA, the FDA's open database. A sentence that sexual dysfunction continued after treatment was stopped stood on 151 of the 181 labels in that database that name finasteride, and on each of them among the adverse reactions, in no warnings section. Of the 30 without it, 10 are hair products with labels in the Drug Facts style, 5 are listings of compounded solutions for the skin, 2 have no text on adverse reactions, and 13 are older labels of 5 mg tablets with an earlier list of adverse reactions. A table cell or list line is shown whole, as the text prints it. Some of them also name side effects that are not sexual. | Text for professionals PROPECIA® (finasteride) tablets for oral use: Full Prescribing InformationPropecia tablets 1 mg, Organon LLC · Read in the government's medicines database: DailyMedAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; 2 related documents, with such a sentence; 3 related documents, with no such sentence | Text revisedChecked |
| Canada | Sexual side effects that continue after stopping8 ADVERSE REACTIONS · 8.5 Post-Market Adverse Reactions Sexual side effects that continue after stopping8 ADVERSE REACTIONS · 8.5 Post-Market Adverse Reactions The same text also says8 ADVERSE REACTIONS · 8.5 Post-Market Adverse Reactions This sentence stands in the list of adverse reactions. The warnings section of this text has no entry on sexual function. Texts for other products in this country do not all say the same. The ones we read are on the full record. This text names sexual side effects in several places that this row does not show. Together those passages are too long to reproduce here. The document link in this row opens the text. That they are not shown says nothing about how common these side effects are. A table cell or list line is shown whole, as the text prints it. Some of them also name side effects that are not sexual. | Text for professionals PRODUCT MONOGRAPH INCLUDING PATIENT MEDICATION INFORMATION: PrPROPECIA® finasteride tablets, Film-coated Tablets 1 mg, USPPropecia film-coated tablets 1 mg, Organon Canada Inc. · Read in the regulator's own database: Drug Product DatabaseAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; 2 related documents, with no such sentence | Text revisedChecked |
| Australia | Sexual side effects that continue after stoppingSection 4.8 · Post-marketing experienceIn section 4.8, under post-marketing experience, Australia's product information for Propecia lists a lower sex drive, and sexual dysfunction (erection and ejaculation problems), each as having gone on after the treatment was stopped.Summarised, not quoted, because of the TGA's access terms. The same text also saysSection 4.8 · Post-marketing experienceThe text says these reports come from a group of unknown size, so how often this happens, and whether the medicine is the cause, cannot always be established.Summarised, not quoted, because of the TGA's access terms. The regulator's site asks readers to accept its terms before it shows this text. This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals AUSTRALIAN PRODUCT INFORMATION PROPECIA (finasteride) TabletsPROPECIA, Organon Pharma Pty Ltd · Read in the regulator's own database: TGA eBSAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence | Text revisedChecked |
| New Zealand | Sexual side effects, as listed4.8 Undesirable effects · Adverse events identified during clinical trials The same text also says4.8 Undesirable effects · Adverse events identified during clinical trials Sexual side effects that continue after stopping4.8 Undesirable effects · Adverse events identified during postmarketing experience · Psychiatric disorders: Sexual side effects that continue after stopping4.8 Undesirable effects · Adverse events identified during postmarketing experience · Reproductive system and breast disorders: The same text also says4.8 Undesirable effects · Adverse events identified during postmarketing experience This sentence stands in the list of adverse reactions. The warnings section of this text has no entry on sexual function. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals New Zealand Data Sheet, PROPECIAPropecia 1 mg film coated tablet, Organon (New Zealand) Limited · Read in the regulator's own database: MedsafeAlso on record: 1 more text for professionals, with such a sentence; patients' leaflet, with such a sentence; related document, with such a sentence | Text revisedChecked |
| Germany | Sexual side effects, as listed4.8 Nebenwirkungen · Psychiatrische Erkrankungen: · Gelegentlich* Sexual side effects, as listed4.8 Nebenwirkungen · Erkrankungen der Geschlechtsorgane und der Brustdrüse: · Gelegentlich* Sexual side effects that continue after stopping4.8 Nebenwirkungen The same text also says4.8 Nebenwirkungen Sexual side effects, as listed4.8 Nebenwirkungen This is the holder's own copy. The regulator's database asks visitors to accept its terms first, which we did not do. This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals Fachinformation (Zusammenfassung der Merkmale des Arzneimittels)Propecia® 1 mg Filmtabletten, Organon Healthcare GmbH · Read on the holder's own site: Organon Healthcare GmbHAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; patients' leaflet, with no such sentence; 2 related documents, with such a sentence; related document, with no such sentence | Text revisedChecked |
| France | Sexual side effects, as listed4.8. Effets indésirables · Affections psychiatriques · Peu fréquent* Sexual side effects, as listed4.8. Effets indésirables · Affections des organes de reproduction et du sein · Peu fréquent* Sexual side effects that continue after stopping4.8. Effets indésirables The same text also says4.8. Effets indésirables Sexual side effects, as listed4.8. Effets indésirables The text itself prints no date of revision. An official list of medicines we read shows the originator product as cancelled, revoked or archived. This is the text of another product, the one named in this row. This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals Résumé des Caractéristiques du ProduitFINASTERIDE ARROW LAB 1 mg, comprimé pelliculé, ARROW GENERIQUES · Read in the government's medicines database: Base de données publique des médicamentsAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; patients' leaflet, with no such sentence; 9 related documents, with such a sentence; 3 related documents, with no such sentence | Updated by the regulatorChecked |
| Italy | Sexual side effects, as listed4.8 Effetti indesiderati · Disturbi psichiatrici: · Non comune* Sexual side effects, as listed4.8 Effetti indesiderati · Patologie dell’apparato riproduttivo e della mammella: · Non comune* The same text also says4.8 Effetti indesiderati Sexual side effects that continue after stopping4.8 Effetti indesiderati Sexual side effects, as listed4.8 Effetti indesiderati The text itself prints no date of revision. This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals Riassunto delle caratteristiche del prodottoPropecia 1 mg compresse rivestite con film, Organon Italia S.r.l. · Read in the regulator's own database: Banca Dati FarmaciAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; 2 related documents, with such a sentence; 2 related documents, with no such sentence | Made available by the regulatorChecked |
| Spain | Sexual side effects, as listed4.8. Reacciones adversas · Trastornos psiquiátricos: · Poco frecuentes* Sexual side effects, as listed4.8. Reacciones adversas · Trastornos del aparato reproductor y de la mama: · Poco frecuentes* The same text also says4.8 Reacciones adversas Sexual side effects that continue after stopping4.8. Reacciones adversas Sexual side effects, as listed4.8. Reacciones adversas This text also has a warning about changes in mood that names sexual dysfunction as something that may contribute to them. That warning says nothing about sexual side effects continuing after stopping. It is not reproduced here, because this record shows the sexual side effects a text lists and whether it says they continue after stopping. The document link in this row opens the text. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Text for professionals Ficha técnicaPropecia 1 mg comprimidos recubiertos con película, Organon Salud, S.L. · Read in the regulator's own database: CIMAAlso on record: 1 more text for professionals, with such a sentence; 2 patients' leaflets, with such a sentence; patients' leaflet, with no such sentence; related document, with no such sentence | Text revisedChecked |
| Brazil | Sexual side effects, as listed8. QUAIS OS MALES QUE ESTE MEDICAMENTO PODE ME CAUSAR? · Reação comum (ocorre entre 1% e 10% dos pacientes que utilizam este medicamento): Sexual side effects, as listed8. QUAIS OS MALES QUE ESTE MEDICAMENTO PODE ME CAUSAR? · Reação incomum (ocorre entre 0,1% e 1% dos pacientes que utilizam este medicamento): The same text also says8. QUAIS OS MALES QUE ESTE MEDICAMENTO PODE ME CAUSAR? Sexual side effects that continue after stopping8. QUAIS OS MALES QUE ESTE MEDICAMENTO PODE ME CAUSAR? · Frequência desconhecida: durante a comercialização do medicamento, as seguintes reações foram relatadas voluntariamente, não sendo possível estimar o tamanho da população exposta: Sexual side effects that continue after stopping8. QUAIS OS MALES QUE ESTE MEDICAMENTO PODE ME CAUSAR? · Frequência desconhecida: durante a comercialização do medicamento, as seguintes reações foram relatadas voluntariamente, não sendo possível estimar o tamanho da população exposta: Sexual side effects that continue after stopping8. QUAIS OS MALES QUE ESTE MEDICAMENTO PODE ME CAUSAR? · Frequência desconhecida: durante a comercialização do medicamento, as seguintes reações foram relatadas voluntariamente, não sendo possível estimar o tamanho da população exposta: This is the holder's own copy. The regulator's database refused our requests (it blocks by country; we asked from Denmark). An official list of medicines we read shows the originator product as cancelled, revoked or archived. This is the text of another product, the one named in this row. Texts for other products in this country do not all say the same. The ones we read are on the full record. | Patient leaflet finasterida, EMS S/A, comprimido revestido 1 mg: bula para o pacienteFinasterida 1 mg comprimido revestido, EMS S/A · Read on the holder's own site: Sara – Plataforma Oficial de Bulas Digitais de Medicamentos do Grupo EMSAlso on record: 2 texts for professionals, could not be opened; 3 more patients' leaflets, with such a sentence; 2 more patients' leaflets, could not be opened | Text approvedChecked |
| India | Sexual side effects that continue after stoppingUndesirable Effects · Postmarketing Experience · Reproductive System: The same text also saysUndesirable Effects · Postmarketing Experience This is the holder's own copy. This regulator publishes no database of such texts. This sentence stands in the list of adverse reactions. The warnings section of this text has no entry on sexual function. Texts for other products in this country do not all say the same. The ones we read are on the full record. This text names sexual side effects in several places that this row does not show. Together those passages are too long to reproduce here. The document link in this row opens the text. That they are not shown says nothing about how common these side effects are. A table cell or list line is shown whole, as the text prints it. Some of them also name side effects that are not sexual. | Text for professionals FINPECIA TabletsFinpecia tablets (finasteride IP 1 mg, film-coated), Cipla Ltd. · Read on the holder's own site: Cipla (ciplamed.com)Also on record: 1 more text for professionals, with such a sentence | Text revisedChecked |
Brand names
These are the brand names of finasteride we saw in the official lists, compendia and regulators' pages we opened on or after 14 October 2026. A country may have more.
- Propecia
- United Kingdom, United States, Canada, New Zealand, Germany, Italy, Spain
- Proscar
- United Kingdom, United States, Canada, Germany, Italy, Spain
- Chibro-Proscar
- France
- Ricit
- New Zealand
- Prostide
- Italy
- Genaprost
- Italy
- Finastid
- Italy
- Asterid
- Italy
- Ridestin
- Italy
- Finestar
- Italy
- Fendazel
- Italy
- Stecur
- Italy
- Sitas
- Italy
- Finacapil
- Italy
- Ormicton
- Italy
- Carefinast
- Italy
- Finedor
- Italy
- Terip
- Italy
- Alocare
- Spain
- Litace
- Spain
- Maxpil
- Spain
- Excalv
- Brazil
- Finalop
- Brazil
- Finarid
- Brazil
- Finastil
- Brazil
- Prohair
- Brazil
What is not known
- How often PFS happens is unknown. The UK text for professionals says the frequency of the side effects reported after marketing, among them sexual dysfunction that persisted after treatment was stopped, “cannot be determined”, because they come from spontaneous reports. (source)
Code and reporting
In a report to a medicines regulator, the term is Post 5-alpha-reductase inhibitor syndrome (MedDRA code 10082430). Where to report, country by country
Every row in this table was checked on or after . To quote this record, name SIDEfxHUB and give this page's address. All medicines and countries · The whole record as a file: JSON · CSV · How these texts are checked
You may reuse this record under CC BY 4.0 if you credit SIDEfxHUB and give this page's address. The licence covers our compilation, not the texts quoted in it, in the original or in our translation, and not the article above.