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 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.

Up to and including 1 July 2026 the MHRA has not received any Yellow Card reports which include anti-androgen withdrawal syndrome as a suspected adverse reaction.

Reporters are asked to submit Yellow Card reports even if they only have a suspicion that the medicine or vaccine may have caused the adverse reaction. A list of the recognised suspected adverse reactions is provided in the information for healthcare professionals and the recipient information, with further information available on the GOV.UK website.

Answering the question raised by the Hon. Member would require the Medicines and Healthcare Products Agency staff to go through a large volume of data manually. This is because the information is not held in such a way to be able to filter by the requested categories.

The sections (a) and (b) would require a data extraction to identify all reports received from members of the public over the last five years. Following this, a manual review would need to be undertaken of every report to cross reference the suspect drug against all active licenses at the time of reporting for each individual case and would thereby incur disproportionate cost. Section (c) is information which is not held in the Yellow Card database.

The Guide to Parliamentary Work sets here out that there is an advisory cost limit known as the disproportionate cost threshold which is the level above which departments can decide not to answer a written question. The Guide to Parliamentary Work is published online and is available at the following link:

https://www.gov.uk/government/publications/guide-to-parliamentary-work

I refer the Hon. Member to the answer I gave on 31 March 2026 to Question 122732.

The Yellow Card scheme collects reports of suspected adverse drug reactions, medical device incidents, and concerns about the safety and quality of medicines. Where appropriate, reports raising potential counterfeit, compliance, or safety issues may be referred to relevant teams within the Medicines and Healthcare products Regulatory Agency (MHRA) for consideration of regulatory or enforcement action.

However, this information is not held in a format that readily allows the MHRA to identify how many reports submitted by members of the public resulted in enforcement action in relation to counterfeit medicines, unapproved medicines in the UK, and medicines which are authorised for supply in the United Kingdom but supplied through unregulated channels. Extracting this information from Yellow Card reports would require a manual review of individual records and would incur disproportionate cost. The MHRA is therefore unable to provide the requested figures for each of the past five years.

The Medicines and Healthcare products Regulatory Agency (MHRA) is committed to continually strengthening the Yellow Card scheme to support patient safety. The MHRA regularly promotes awareness through public health campaigns, conferences, established networks, and new educational resources available on the Yellow Card website. Further information is available on the MHRA website at the following link:

https://www.gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency

Reporting rates through spontaneous reporting systems, such as the Yellow Card Scheme, are highly variable, and dependent not just on the condition, but other factors such as the product, public interest, and media attention. As such, the MHRA does not hold estimates of under reporting rates for these conditions.

The MHRA is expanding and improving digital reporting routes. Every National Health Service webpage relating to a medicine or vaccine now links to the Yellow Card scheme, and the MHRA is working with NHS colleagues to enhance integration with the NHS App to increase visibility and reporting by the public. Yellow Card reporting is now embedded in almost all general practice clinical IT systems, enabling healthcare professionals to submit reports directly on behalf of patients.

Over recent years, the MHRA has delivered a major upgrade programme to modernise the Yellow Card scheme’s technology and infrastructure. This includes improving the quality and timeliness of submitted information, making it easier to report, adding conditional questions to reduce follow up, and support real time signal detection of safety issues.

The Yellow Card app has also been modernised to mirror the website, broaden reporting options, including defective and counterfeit medicines, and improve access to safety data. Multifactor authentication has been introduced to enhance account security and enable future integration with the NHS login. The app has also been upgraded to a progressive web application, providing a seamless and engaging user experience across devices.

Together, these improvements increase public awareness, make reporting, including of myocarditis and pericarditis, easier, and enhance the MHRA’s ability to identify and assess emerging safety concerns across healthcare products.

The Medicines and Healthcare products Regulatory Agency (MHRA) is committed to continually strengthening the Yellow Card scheme to support patient safety. The MHRA regularly promotes awareness through public health campaigns, conferences, established networks, and new educational resources available on the Yellow Card website. Further information is available at the following link:

https://www.gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency

The MHRA is expanding and improving digital reporting routes. Every National Health Service webpage relating to a medicine or vaccine now links to the Yellow Card scheme, and the MHRA is working with NHS colleagues to enhance integration with the NHS App to increase visibility and reporting by the public. Yellow Card reporting is now embedded in almost all general practice clinical IT systems, enabling healthcare professionals to submit reports directly on behalf of patients.

Over recent years, the MHRA has delivered a major upgrade programme to modernise the Yellow Card scheme’s technology and infrastructure. This includes improving the quality and timeliness of submitted information, making it easier to report, adding conditional questions to reduce follow up, and support real time signal detection of safety issues.

The Yellow Card app has also been modernised to mirror the website, broaden reporting options, including defective and counterfeit medicines, and improve access to safety data. Multi‑factor authentication has been introduced to enhance account security and enable future integration with NHS login. The app has also been upgraded to a progressive web application, providing a seamless and engaging user experience across devices.

Together, these improvements increase public awareness, make reporting easier, and enhance the MHRA’s ability to identify and assess emerging safety concerns across healthcare products.

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 Medicines and Healthcare products Regulatory Agency (MHRA) is an executive agency of the Department, with responsibility for ensuring medicines meet appropriate standards of safety, quality, and efficacy.

In 2021, the MHRA published a Public Assessment Report (PAR), reviewing the available evidence for topical steroid withdrawal (TSW) reactions, which can be found at the following link:

https://www.gov.uk/government/publications/topical-steroid-withdrawal-reactions-a-review-of-the-evidence

To inform this report, a comprehensive review of the available evidence was undertaken. This included an assessment of data from Yellow Card reports to identify suspected spontaneous cases of TSW reactions associated with topical corticosteroids on the Yellow Card database, as well as information from the published literature and other medicines regulators. The review considered whether regulatory action was required to minimise the risk of these events.

The PAR resulted in two Drug Safety Updates in 2021 and 2024 which aimed to raise awareness on the risk of TSW reactions and introduce new labelling. Both updates are available, respectively, at the following two links:

https://www.gov.uk/drug-safety-update/topical-corticosteroids-information-on-the-risk-of-topical-steroid-withdrawal-reactions

https://www.gov.uk/drug-safety-update/topical-steroids-introduction-of-new-labelling-and-a-reminder-of-the-possibility-of-severe-side-effects-including-topical-steroid-withdrawal-reactions

The MHRA uses the Medical Dictionary for Regulatory Activities (MedDRA) to code suspected adverse drug reactions reported by patients and healthcare professionals via the Yellow Card scheme. MedDRA is an international, clinically validated medical terminology used by regulatory authorities and the biopharmaceutical industry throughout the entire regulatory process, from pre-marketing to post-marketing safety monitoring. MedDRA is updated twice annually, and new terms can be proposed by any MedDRA users. Following the publication of the PAR, the term “Topical steroid withdrawal reaction” was added to MedDRA as a lower level term in version 24.1 and made available to users of the Yellow Card website in February 2022 as part of routine updates. This helps to ensure that more reports pertaining to TSW reactions are appropriately captured. The MHRA continues to closely monitor Yellow Card reports submitted for suspected TSW reactions.

The MHRA continues to engage with the British Association of Dermatologist who have also released a statement, which is available at the following link:

https://cdn.bad.org.uk/uploads/2024/02/22095550/Topical-Steroid-Withdrawal-Joint-Statement.pdf

The Medicines and Healthcare products Regulatory Agency (MHRA) publishes information in the form of interactive Drug Analysis Profiles which can be accessed here on the Yellow Card website, at the following link:

https://yellowcard.mhra.gov.uk/idaps

You will be able to access a complete listing of all suspected adverse drug reactions that have been reported to the MHRA via the Yellow Card scheme for all medicines, including medicines used to treat coughs and colds. This includes all reports received from healthcare professionals, members of the public, and pharmaceutical companies.

Please note information regarding whether a drug was prescribed or purchased over the counter is not mandatory to provide on a Yellow Card and as such we do not capture this information in a structured data field to be able to provide as part of this request.

The Medicines and Healthcare Products Regulatory Agency (MHRA) is an executive agency of the Department and regulates medicines, for human use, medical devices, and blood components for transfusion in the United Kingdom.

If a “medical supplement” was covered by the definition of a medicinal product as set out in the Human Medicines Regulations 2012, or the definition of a medical device under Medical Devices Regulations, it would fall under the remit of the MHRA and would be subject to the relevant regulatory requirements. Food supplements are regulated by the Food Standards Agency.

Ongoing efforts to raise awareness of the Yellow Card scheme will enhance public understanding of the scheme’s remit and the range of healthcare products it covers, including the reporting of suspected side effects associated with herbal and/or homeopathic medicines, as set out in existing information and general awareness materials available on the Yellow Card scheme website.

The Medicines and Healthcare products Regulatory Agency (MHRA) is committed to improving patient safety and strategically runs regular public health campaigns to raise awareness of patient safety in healthcare products and the importance of reporting to the Yellow Card scheme, which relies on voluntary reporting by healthcare professionals and the public, including patients, parents, and care givers. Further information on the MHRA is available at the following link:

https://www.gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency

A primary platform for education and awareness is the MHRA’s dedicated Yellow Card scheme website, which is regularly updated with educational resources, including Continuing Professional Development accredited e-learning modules, waiting-room videos, posters, and real-world case studies to support understanding of how and what to report as well as the importance of reporting. In 2025, the MHRA launched a new Yellow Card Partner Toolkit containing a package of materials specifically designed to support other organisations and networks in encouraging patient reporting.

To strengthen local engagement with the public, the MHRA commissions six Yellow Card Centres across the United Kingdom, covering the North and Yorkshire, the North West, the West Midlands, Scotland, Wales, and Northern Ireland, and which focus on education and the promotion of reporting with the public and healthcare professionals, as well as their representative organisations within their regions.

Additionally, all MHRA safety alerts and guidance signpost users to the Yellow Card scheme, and by law, every patient information leaflet that comes with a medicine includes information signposting patients to report suspected side effects via the Yellow Card scheme. There is also information on the importance of reporting to the Yellow Card scheme on all repeat paper prescriptions given to patients.

On World Patient Safety Day, most recently 17 September 2025, the MHRA announced that statutory relationships, sex, and health education guidance for schools in England would, for the first time, include information on recognising side effects and reporting them via the Yellow Card scheme. This initiative introduces children and young people to patient safety early, empowering them to speak up and contribute to safer healthcare.

The MHRA also proactively promotes awareness through presence at conferences such as the annual Health and Safety Journal Patient Safety Congress. In addition, the MHRA also supports a number of campaigns including MedSafetyWeek, which is now an annual international social media campaign which includes 117 countries that the MHRA initiated 10 years ago, to raise awareness of medicines safety and adverse incident reporting.

The MHRA has worked with the National Health Service to ensure that there are links to Yellow Card across every single NHS page relating to a medicine or vaccine, and the MHRA is also building upon this by working with NHS colleagues to support better links between the NHS app and Yellow Card, aiming for increased visibility of the Yellow Card scheme and improved reporting of suspected reactions by the public.

Together, these measures increase public awareness of the Yellow Card scheme, helping protect patient safety and strengthen monitoring of medicines and medical devices.

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.

The MHRA has received a total of eight United Kingdom reports through the Yellow Card scheme associated with the reaction term aphantasia, from 1 January 2021 up to and including 12 December 2025. The following table shows a yearly breakdown of reports associated with aphantasia received from 1 January 2021 up to and including 12 December 2025:

In addition, the following table shows a yearly breakdown of reports received by substance associated with aphantasia from 1 January 2021 up to and including 12 December 2025:

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. The reporter does not have to be sure of a causal association between the drug and the reactions, as 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 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.

The MHRA has received a total of 11,348 United Kingdom reports through the Yellow Card scheme associated with reaction term tinnitus, including worsening of tinnitus, from 1 January 2014 up to and including 27 November 2025. The table in the document attached provides a yearly breakdown of reports associated with tinnitus. It also provides a yearly breakdown of reports received by the substance associated with tinnitus. 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 table in the attached document. The following table shows a yearly breakdown of reports associated with tinnitus received from 1 January 2014 up to and including 27 November 2025:

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, and the reporter does not have to be sure of a causal association between the drug and the reactions, as 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.

Visual snow syndrome (VSS) was officially recognized in 2025 with a unique code in the eleventh edition of the International Classification of Diseases by the World Health Organization. Very few cases of VSS have been reported with 22 individual drugs or vaccines through the Yellow Card scheme.

VSS is a rare disorder and the underlying cause currently unknown. The Medicines and Healthcare products Regulatory Agency (MHRA) keeps all licensed medicines and vaccines under close monitoring and any potential signal of an association between a medicine or vaccine exposure and development of VSS will be rigorously assessed through the MHRA’s multidisciplinary signal review process and added to individual product information when there is data available to support regulatory action.

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 the 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 11,348 United Kingdom based reports through the Yellow Card scheme associated with reaction term tinnitus, including worsening of tinnitus, from 1 January 2014 up to and including 27 November 2025. The reports received between 2014 and 2025 were for a wide range of medicinal products which include antidepressants, hormonal medicines, vaccines, antipsychotics, antibiotics, cardiovascular medicines, drugs used to treat attention deficit hyperactivity disorder, sedatives, drugs used to treat dementia and diabetes, drugs used to treat osteoporosis, Parkinson’s disease, and pain. The following table shows a yearly breakdown of reports associated with tinnitus, from 2014 to 2025, and in total:

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, and the reporter does not have to be sure of a causal association between the drug and the reactions, as 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. All fatal reports, including those reporting completed suicide, are assessed by the MHRA, and cumulative information is reviewed at regular intervals.

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 the 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 44 United Kingdom based reports through the Yellow Card scheme associated with the reaction term visual snow syndrome received up to and including 25 November 2025. The table attached shows the yearly breakdown of substances associated with visual snow syndrome, each year from 2017 to 2025.

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, and the reporter does not have to be sure of a causal association between the drug and the reactions, as 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. All fatal reports, including those reporting completed suicide, are assessed by the MHRA and cumulative information is reviewed at regular intervals.

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 their independent advisory committee, the Commission on Human Medicines, where appropriate to inform regulatory decisions.

The MHRA uses the Medical Dictionary for Regulatory Activities (MedDRA) to code suspected adverse drug reactions reported by patients and healthcare professionals via the Yellow Card scheme. MedDRA is an international, clinically validated medical terminology used by regulatory authorities and the biopharmaceutical industry throughout the entire regulatory process, from pre-marketing to post-marketing safety monitoring. MedDRA is updated twice annually, and new terms can be proposed by any MedDRA users. The term Post Selective Serotonin Reuptake Inhibitor Sexual Dysfunction (PSSD) was added to MedDRA as a lower-level term in version 24.1 which was and implemented by the MHRA as a term available to users of the Yellow Card website in February 2022 as part of routine updates.

As part of current routine MHRA processes, Yellow Card reports are not recoded to reflect the changes in the reaction terms available but remain as reported with the terms selected by the original reporter.

As a lower-level term in MedDRA, PSSD is recorded if the reporter has specifically used this term at the time of the report, and since this term can include a wide range of symptoms it would not be appropriate to recode cases not reporting this specific term received prior to 2021. All Yellow Card reports received prior to the availability of PSSD as a MedDRA term will have the individual symptoms reported coded as MedDRA terms and available for signal detection and assessment processes.

A total of 52 reports that describe increased sexual arousal suspected to be associated with the use of medicines or vaccines have been received through the Yellow Card scheme. The reports were received between 2014 and 2025 for a wide range of medicinal products which include antidepressants, hormonal medicines, vaccines, antipsychotics, antibiotics, cardiovascular medicines, drugs used to treat attention deficit hyperactivity disorder, sedatives, drugs used to treat dementia and diabetes, and single reports for drugs used to treat osteoporosis, Parkinson’s disease, and pain.

The term increased sexual arousal itself is not in the product information for any of the above classes of medicines, however terms such as increased libido and hypersexuality are reflected in product information for medicines used to treat Parkinson’s disease. The following table shows a breakdown of all spontaneous Yellow Card Reports the Medicines and Healthcare products Regulatory Agency (MHRA) received from 1 January 2014 to 4 November 2025, where the MedDRA, a categorisation of medical terminology, Lowest Level Term (LTT) ‘increased sexual arousal’ was reported:

In addition, the following able shows a breakdown of all spontaneous Yellow Card Reports the MHRA received from 1 January 2014 to 4 November 2025 where the MedDRA LLT ‘increased sexual arousal’ was reported, broken down by substance: