Men on finasteride asked to stay vigilant for possible psychiatric and sexual side effects

After a comprehensive review of the safety of finasteride, the Medicines and Healthcare products Regulatory Agency (MHRA) is asking men taking this medicine to stay vigilant for potential psychiatric (mental health) and sexual side effects.

As a recommendation of the review, a patient alert card will be introduced into the finasteride pack this year to raise awareness of these risks and help to ensure that patients are informed on what to do if they experience these side effects. As patients may not notice changes to their mood, they are encouraged to show this card, and the patient leaflet, to friends and family. Healthcare professionals have also been reminded to monitor patients for such side effects through a new Drug Safety Update.

Finasteride, a medicine used by men to treat hair loss (1 mg-dose, brand name Propecia) and benign (non-cancerous) enlargement of the prostate (5 mg-dose, brand name Proscar), has been reported to cause depressed mood, depression, suicidal thoughts and sexual dysfunction (including decreased sex drive and inability to get and maintain an erection). In some cases, sexual dysfunction has persisted in patients even after they have stopped taking finasteride. However, there is a lack of awareness of these potential side effects.

Before starting finasteride, patients should inform their prescriber of any personal history of depression or suicidal thoughts. Men taking finasteride 1 mg (Propecia) for hair loss who develop depression or suicidal thoughts must immediately stop treatment and contact their doctor as soon as possible. Those prescribed finasteride 5 mg (Proscar) for benign enlargement of the prostate who develop such symptoms, should speak to their doctor urgently for further medical advice.

If patients experience any problems with sexual function, such as inability to get and maintain an erection or decrease in sex drive, they should discuss this with their prescriber or doctor. All patients are reminded to always read the leaflet that is provided alongside the medicine, which contains important information about taking finasteride and a full list of known possible side effects.

Dr Alison Cave, MHRA Chief Safety Officer, said:

It’s crucial that patients are aware of vital information about the medicines they’re taking.

The new patient alert cards aim to raise awareness among men taking finasteride about the potential for psychiatric and sexual side effects, so they can make an informed decision about their treatment and know what to do if they experience these side effects.

If you’re taking finasteride 1 mg (Propecia) for hair loss and develop depression or suicidal thoughts, stop treatment and contact your doctor. If these symptoms develop with finasteride 5 mg (Proscar), for benign enlargement of the prostate, consult your doctor immediately for further advice. Any concerns about sexual dysfunction should be discussed with your healthcare professional.

Remember to always read the leaflet inside the pack as it includes important information on how to take finasteride and its possible side effects. Please continue to report any suspected side effects from finasteride via the MHRA Yellow Card scheme.

The MHRA completed a review of the safety of finasteride following concerns raised by patients regarding a lack of awareness of these side effects amongst patients and healthcare professionals. The MHRA reviewed the available evidence, including Yellow Card reports, published scientific literature and actions by other regulators, and this was considered by the Pharmacovigilance Expert Advisory Group (PEAG) of the Commission on Human Medicines (CHM). 

The PEAG noted that the product information for finasteride contains information regarding the risk of depression and suicidal ideation and the potential of persistent sexual side effects after discontinuation with finasteride. However, these side effects do not appear to be well known by prescribers and patients, and therefore recommended the introduction of a patient card to increase awareness about these risks.

Notes to editors

• Further information is available in the Drug Safety Update and Public Assessment Report.
• Finasteride is a 5 alpha-reductase-type-2 inhibitor. The 1 mg dose (Propecia) is indicated in men 18 to 41 years of age for the treatment of male pattern hair loss (androgenetic alopecia). The 5 mg dose (Proscar) is indicated for the treatment and control of benign prostatic hyperplasia in adults. 
• While finasteride 5 mg (Proscar) is prescribed by the NHS, finasteride 1 mg (Propecia) is only available via a private prescription and is commonly prescribed online, which may increase the risk that these side effects are not communicated sufficiently.
• A previous Drug Safety Update for finasteride was issued in 2017, but the evidence concerning the potential persistence of sexual dysfunction was insufficient at that time.
• Up to 5 April 2024, the MHRA has received 281 Yellow Card reports of finasteride (both 1 mg and 5 mg formulations) linked to finasteride and depressed mood disorders and suicidal and self-injurious behaviours. The majority of these reports are related to depressed mood disorders with 14 of the reports relating to suicidal behaviours. There are 426 Yellow Card reports associated with sexual dysfunction. There is widespread use of this product with average prescriptions of finasteride 5 mg of approximately 20,000 per month. The MHRA is unable to get accurate usage data for finasteride 1 mg as this is prescribed privately.
• The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for regulating all medicines and medical devices in the UK by ensuring they work and are acceptably safe.  All our work is underpinned by robust and fact-based judgements to ensure that the benefits justify any risks. 
• The MHRA is an executive agency of the Department of Health and Social Care. 
• For media enquiries, please contact 020 3080 7651 or [email protected].