The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for ensuring medicines, medical devices, and blood components for transfusion meet applicable standards of safety, quality, and efficacy. The MHRA rigorously assesses available data, including from the Yellow Card scheme, and seeks advice from the Commission on Human Medicines, the MHRA’s independent advisory committee, where appropriate, to inform regulatory decisions including amending the product information.

Since 1 January 2019 up to and including 1 July 2026, the MHRA has received nine Yellow Card reports which include post 5-alpha-reductase inhibitor syndrome as a suspected adverse reaction. One report was received in 2023, with six reports being received in 2025, and five in 2026 thus far. The following table shows a breakdown of the medicines included in the nine Yellow Card reports received between 1 January 2019 and 1 July 2026, noting that one report can contain more than one medicine, and as such the sum of reports in the table will not equal the total number of unique reports:

Source: MHRA Yellow Card database.

It is important to note that Yellow Card reports capture adverse reactions as reported by the patient or healthcare professional, and this could be a syndrome or diagnosis, or underlying signs and symptoms. For a full breakdown of adverse reactions reported for medicines in the table above please view our interactive drug analysis profiles on the Yellow Card website.

It is important to note that a reaction reported to the Yellow Card scheme does not necessarily mean it has been caused by the medicine, only that the reporter had a suspicion it may have. Underlying or concurrent illnesses may be responsible, or the events could be coincidental. The number of reports received cannot be used as a basis for determining the incidence of a reaction, as neither the total number of reactions occurring, nor the number of patients using the drug, is known.

The Prescription Cost Analysis (PCA) provides the total number of prescription items of each medicine dispensed in the community in England. The following table shows the total number of items in each calendar year from 2014 to 2025 that have been dispensed in England:

This is based on the information within the PCA for the British National Formulary chemical substance of Isotretinoin and Finasteride.

The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for ensuring that medicines, medical devices, and blood components for transfusion meet applicable standards of safety, quality, and efficacy. The MHRA rigorously assesses available data, including from the Yellow Card scheme, and seeks advice from the Commission on Human Medicines, the MHRA’s independent advisory committee, where appropriate, to inform regulatory decisions including amending the product information.

The MHRA has received a total of four United Kingdom reports through the Yellow Card scheme associated with the reaction term Post 5-Alpha Reductase Inhibitor Syndrome from 1 January 2019 up to and including 4 February 2026. The following table shows a yearly breakdown of reports associated with Post 5-Alpha Reductase Inhibitor Syndrome:

In addition, the following table shows a yearly breakdown of reports received by substance associated with Post 5-Alpha Reductase Inhibitor Syndrome:

Please note that each report may list more than one suspect drug. Therefore, the total number of reports received cannot be accurately derived from the figures presented in the above table.

It is important to note that anyone can report to the MHRA’s Yellow Card scheme and the recording of these reports in the Yellow Card database does not necessarily mean that the adverse reactions have been caused by the suspect drug. Many factors must be considered in assessing causal relationships, including temporal association, the possible contribution of concomitant medication, and the underlying disease. We encourage reporters to report suspected adverse reaction reports, as the reporter does not have to be sure of a causal association between the drug and the reactions, a suspicion will suffice.

The number of reports received cannot be used as a basis for determining the incidence of a reaction, as neither the total number of reactions occurring, nor the number of patients using the drug, is known.

The following table shows the requested information in each calendar year between 2014 and 2024, as well as between January and November 2025, and that has been dispensed in England regardless of where prescribed:

Source: NHS Business Services Authority, Prescription Costs Analysis (PCA)

Notes:

1. This is based on the information within the PCA for the British National Formulary (BNF) chemical substance of Finasteride and Dutasteride.
2. The PCA provides total number of prescription items of each medicine dispensed in the community in England.

There are no current plans to review the legal avenues of online prescribing and the dispensing of prescription-only medications.

Decisions about what medicines to prescribe are made by the doctor or healthcare professional responsible for that part of the patient’s care, and prescribers are accountable for their prescribing decisions, irrespective of the forum in which these decisions are made.

Clinicians are expected to work with patients to make decisions about their care and treatment as part of shared decision making, including discussing risks, benefits, and possible consequences of different options, in line with professional guidelines laid down by the General Medical Council, which are available at the following link:

https://www.gmc-uk.org/professional-standards/the-professional-standards/good-practice-in-prescribing-and-managing-medicines-and-devices

The Medicines and Healthcare products Regulatory Agency’s (MHRA) role is to continually monitor the safety of medicines during their use. We have robust, safety monitoring and surveillance systems in place for all healthcare products, including finasteride. As part of our monitoring and surveillance activities, we take into account any changes in the usage of a particular medicine.

Finasteride containing medicines are prescription only medicines. This means they must be prescribed by a doctor or other authorised health professional, and must be dispensed from a pharmacy or from another specifically licensed premises.

The MHRA has recently completed an extensive safety review into finasteride, with the subsequent updates to the product information having been implemented, and the development of a patient alert card is underway. We also published a Drug Safety Update to raise awareness amongst healthcare professionals of the adverse psychiatric and sexual side effects. We are aware that the European Medicines Agency has launched a review, and we are monitoring this closely. Further information on the Drug Safety Update is available at the following link:

https://www.gov.uk/drug-safety-update/finasteride-reminder-of-the-risk-psychiatric-side-effects-and-of-sexual-side-effects-which-may-persist-after-discontinuation-of-treatment

Please be reassured that the MHRA continuously monitors the safety of finasteride via information from various sources, including the published literature. Information from all sources is carefully screened and may identify unexpected side effects, indicate that certain side effects occur more commonly than previously believed, or that some patients are more susceptible to some effects than others. If a new side effect is identified, information is carefully considered in the context of the overall side effect profile for the medicine. When necessary, the MHRA may take action to ensure that a medicine is used in a way which minimises risk and maximises benefits to the patient.

Stocks of finasteride tablets currently remain available.

The Department works with NHS England, the devolved administrations, the Medicines and Healthcare products Regulatory Agency, the pharmaceutical industry and others operating in the supply chain, to prevent shortages and expedite resupply where possible.