Propecia Side Effects

UK warnings on finasteride: what the MHRA said in 2024 and 2026

Written by Nick O, UK-based, living with PFS since 2003. Last reviewed: .

In April 2024 and again in May 2026, the UK's medicines regulator, the MHRA, strengthened its warnings about finasteride. Finasteride is sold as Propecia for hair loss and as Proscar for an enlarged prostate. The warnings cover depression, suicidal thoughts and sexual side effects. The MHRA says the sexual side effects can carry on after you stop taking it.

When I took Propecia in 2002 and 2003, there was no warning like this in the pack. This page sets out what the regulator now says, in plain English, with links to the original documents.

At a glance

DateWhat happened
MHRA Drug Safety Update on rare reports of depression and suicidal thoughts with finasteride
MHRA safety review: doctors reminded that sexual side effects may persist after stopping, and a patient alert card announced for finasteride packs
European review confirms suicidal thoughts as a side effect of finasteride 1 mg and 5 mg
MHRA strengthens warnings again: new wording on sexual dysfunction and mood, plus a precautionary warning for dutasteride

The 2024 review

In April 2024 the MHRA published the results of a safety review. Patients had raised concerns that people did not know enough about the side effects. The regulator looked at Yellow Card reports, published research and action taken by other regulators. Its expert advisers recommended two things: a reminder to healthcare professionals, and an alert card inside every pack.

The MHRA said that people had reported sexual dysfunction that “has persisted even after treatment was stopped”. It also said that, although the product information already mentioned this, prescribers and patients were often unaware of it.

Yellow Card reports up to 5 April 2024:

  • 426 reports of sexual dysfunction with finasteride since 1992, including erectile dysfunction and reduced sex drive. In almost half of these, the outcome was recorded as “not recovered” or “not resolved”.
  • 281 reports of depressed mood, suicidal behaviour or self-injury since 1993. 14 of these related to suicidal behaviour.

The MHRA has no accurate usage figures for finasteride 1 mg, because it is not prescribed on the NHS and is only available privately.

What changed in 2025 and 2026

In 2025 a European review, requested by the French medicines agency, confirmed suicidal thoughts as a side effect of finasteride 1 mg and 5 mg tablets. It added a patient card to 1 mg packs across the EU.

In May 2026 the MHRA reviewed the evidence again and went further:

  • The finasteride 1 mg leaflet and prescribing information now say that sexual dysfunction may contribute to mood disorders. They also say that sexual dysfunction has been reported without any change in mood.
  • Dutasteride (Avodart), a similar prostate drug, now carries a precautionary warning that mood changes have been reported with finasteride. The MHRA said the dutasteride data were “very limited”.
  • The UK patient alert cards introduced in 2024 stay in place for both the 1 mg and 5 mg products.

The 2026 update also gave new Yellow Card figures: 170 reports of suicidal thoughts and related terms for finasteride between 1994 and 31 May 2025, including 19 reports of suicide. Most of the reports involved the 1 mg hair-loss tablet. The MHRA notes that a Yellow Card report does not prove the medicine caused the reaction. It also says the research shows mixed results.

What the MHRA tells patients to do

  • Before starting, read the patient card and leaflet, and tell your prescriber if you have ever had depression or suicidal thoughts.
  • Finasteride 1 mg (hair loss): if you develop depression or suicidal thoughts, stop taking it straight away and contact your doctor as soon as possible.
  • Finasteride 5 mg or dutasteride (prostate): if you develop depression or suicidal thoughts, contact your doctor as soon as possible.
  • Sexual side effects such as low sex drive, erection problems or ejaculation problems: talk to your doctor.
  • Tell family and friends that you are taking it. You may not notice changes in your own mood.
  • If you have seriously harmed yourself or feel at serious risk, call 999.

What the warnings don't say

The MHRA confirms that sexual side effects can persist after stopping, but it gives no figures for how often that happens or how long it lasts. It does not use the term “post-finasteride syndrome”, and it does not recommend any treatment for persistent symptoms. Both regulators still say the benefits of these medicines outweigh the risks for their approved uses.

That gap is why personal accounts like mine still matter. You can read my story, and what research has found about possible lasting changes in gene activity.

Report your side effects

If you have had side effects from finasteride, during treatment or after stopping, report them to the MHRA Yellow Card scheme. You don't need a doctor to do it. The MHRA asks you to include when you started and stopped the medicine, and whether the problem began or carried on after you stopped. Reports like these are what led to the 2024 and 2026 changes.

If you are struggling

Persistent side effects can be isolating. If you are having thoughts of suicide, call Samaritans free on 116 123 (24 hours) or visit samaritans.org. In an emergency, call 999.

Sources

This page is a summary of the regulator's published guidance, written by someone affected. It is not medical advice. Speak to your GP or pharmacist about your own situation.