Yellow Card: How To Report An ED Medication Side Effect
 - Guide | Cured Pharmacy

Yellow Card: How To Report An ED Medication Side Effect

HEALTH · 18 MIN READ
Written by Cured Pharmacy
Published on 17 June 2026

If you have ever taken a medication for erectile dysfunction and noticed something unexpected — a pounding headache, a sudden flush of warmth, or something more worrying — you are not alone, and your experience genuinely matters to UK medicine safety. The Yellow Card scheme, run by the Medicines and Healthcare products Regulatory Agency (MHRA), exists precisely so that patients and healthcare professionals can flag side effects from any medication, including those used for erectile dysfunction such as sildenafil and tadalafil. Reporting your experience is straightforward, takes only a few minutes, and contributes directly to the safety of thousands of other men across the UK.

Tarun Kumar, Prescribing Pharmacist at Cured Pharmacy

Medically reviewed by

Tarun Kumar, Prescribing Pharmacist (GPhC 2233073)

Last reviewed: 18 June 2026

Quick Summary

Reporting an ED medication side effect through the Yellow Card scheme is a free, confidential process managed by the MHRA. Whether you experienced a minor inconvenience or a more serious reaction, submitting a report helps improve medicine safety for everyone in the UK.

  • The MHRA Yellow Card scheme allows patients, carers, and healthcare professionals to report suspected side effects from any medicine, including ED treatments.
  • Common ED medications that can be reported include sildenafil (Viagra), tadalafil (Cialis), vardenafil, and avanafil.
  • You can report online, via the Yellow Card app, by post, or through your pharmacist or GP.
  • You do not need a confirmed diagnosis or proof — a suspected link between the medicine and the side effect is sufficient.
  • All reports are treated confidentially and contribute to ongoing national pharmacovigilance data reviewed throughout 2026 and beyond.

ED Side Effect Tracker

Use this tool to log any side effects you have experienced with your ED medication before submitting your Yellow Card report. Tick all that apply.

Table of Contents

  1. What Is the Yellow Card Scheme and Why Does It Exist?
  2. Which ED Medications Can Be Reported?
  3. How to Report an ED Medication Side Effect Step by Step
  4. Common vs Serious ED Medication Side Effects: Know the Difference
  5. What Happens After You Submit Your Yellow Card Report?
  6. Overcoming Common Barriers to Reporting ED Side Effects
  7. ED Medication Side Effect Reference Table
  8. Key Takeaways
  9. When to Seek Professional Advice
  10. Scientific References
  11. Frequently Asked Questions

What Is the Yellow Card Scheme and Why Does It Exist?

The Yellow Card scheme is the UK's national system for collecting and monitoring reports of suspected side effects — formally known as adverse drug reactions (ADRs) — from medicines, vaccines, and medical devices. It is operated by the MHRA, the government body responsible for ensuring that all medicines available in the UK are acceptably safe, effective, and of the right quality. The scheme has been in operation since 1964, originally following the thalidomide tragedy, which demonstrated catastrophically what can happen when medicine safety signals go unmonitored. Today it remains one of the most important post-market surveillance systems in the world.

When a medicine is licensed and sold to the public, clinical trials have tested it on a relatively small and controlled group of participants. Real-world use — across millions of people with different health conditions, lifestyle factors, and other medications — inevitably reveals side effects that trials did not detect. This is why spontaneous reporting systems like the Yellow Card scheme are so vital. Every report submitted by a patient or clinician adds to a growing bank of safety evidence that helps regulators and manufacturers adjust prescribing guidance, update patient information leaflets, or in rare cases withdraw a product entirely. For erectile dysfunction treatments, where millions of men across the UK use medications like sildenafil regularly, patient-reported data is particularly important.

  • The MHRA has received over 1.5 million Yellow Card reports since the scheme's inception.
  • Patients, carers, and healthcare professionals can all submit reports.
  • Reports can relate to prescription medicines, over-the-counter treatments, herbal remedies, and medical devices.
  • You do not need proof — a suspected link is enough to file a report.

Which ED Medications Can Be Reported?

Any medication used to treat erectile dysfunction can be reported through the Yellow Card scheme, whether it was prescribed by a GP, issued by an online pharmacy, or purchased over the counter. The most commonly used ED medications in the UK belong to a class called phosphodiesterase type 5 inhibitors, or PDE5 inhibitors. These medicines work by relaxing the smooth muscle in the blood vessels of the penis, increasing blood flow during sexual arousal. While they are generally well tolerated, they do carry a recognised side effect profile, and individual reactions can vary considerably depending on a person's age, cardiovascular health, other medications, and underlying conditions.

In 2026, sildenafil remains the most widely dispensed ED treatment in the UK, available both on NHS prescription and as a pharmacy-licensed over-the-counter medicine under the brand name Viagra Connect. Tadalafil, which lasts up to 36 hours and is also available as a daily low-dose treatment, is the second most frequently used option. Vardenafil and avanafil are less common but are still prescribed and can equally be the subject of a Yellow Card report. If you have taken any herbal or unlicensed product marketed for sexual performance — including those bought online from unregulated sources — these can also be reported, and in many cases reporting them is especially important as they may contain undisclosed active pharmaceutical ingredients.

  • Sildenafil (brand names: Viagra, Viagra Connect)
  • Tadalafil (brand names: Cialis, Tadalafil daily)
  • Vardenafil (brand name: Levitra)
  • Avanafil (brand name: Spedra)
  • Unlicensed or herbal products marketed for ED

Yellow Card: How to Report an ED Medication Side Effect — A Step-by-Step Guide

The process of using the Yellow Card scheme is genuinely simple, and the MHRA has made significant improvements to the online portal in recent years to make it as accessible as possible. There are four main ways to submit a report: online via the Yellow Card website, through the dedicated Yellow Card smartphone app, by post using a paper Yellow Card form (available from pharmacies), or indirectly by asking your pharmacist or GP to submit one on your behalf. The online route is the quickest and most commonly used.

Before you begin, it helps to have the following information to hand: the name and dose of the ED medication you took, the date you started taking it, when the side effect occurred, a description of what happened, your age and sex, and any other medications or supplements you are currently taking. You do not need a patient number, GP reference code, or formal diagnosis. The MHRA is clear that reports based on suspicion — even if you are uncertain whether the medicine caused the problem — are still valuable and encouraged. Once submitted, you will receive a reference number and, in most cases, a follow-up request for any additional information needed.

  1. Visit yellowcard.mhra.gov.uk or download the Yellow Card app from your phone's app store.
  2. Select "Report a suspected side effect or medical device issue."
  3. Choose whether you are reporting as a patient, carer, or healthcare professional.
  4. Enter details about the medication (name, dose, frequency, start and stop dates).
  5. Describe the side effect clearly, including when it started, how long it lasted, and whether it resolved.
  6. Add any other medications or supplements you were taking at the same time.
  7. Enter your age, sex, and any relevant medical history (optional but helpful).
  8. Submit the form — you will receive a confirmation email with your report reference.

Common vs Serious ED Medication Side Effects: Know the Difference

Understanding which side effects are to be expected and which require urgent attention is one of the most practical things a man taking ED medication can do. Common side effects are those that affect a significant proportion of users — typically defined as occurring in more than one in a hundred people — and are generally mild, temporary, and manageable. These are listed in every medication's patient information leaflet and are well documented in the clinical literature. Knowing that a mild headache after taking sildenafil is normal does not mean it should go unreported if it is troublesome or recurring — but it does mean it is unlikely to require an A&E visit.

Serious side effects, by contrast, are those that pose a direct risk to health and require prompt medical attention. For PDE5 inhibitors, these include priapism (a prolonged erection lasting more than four hours), sudden loss of vision in one or both eyes, sudden hearing loss, severe chest pain, and significant drops in blood pressure. These reactions are rare but can cause permanent damage if not treated immediately. If you experience any of these, you should seek emergency medical help first, and then submit a Yellow Card report once you are safe. Your experience is extremely valuable to the MHRA's ongoing pharmacovigilance work and may help prevent the same thing from happening to someone else. Visiting a regulated UK erectile dysfunction pharmacy ensures you receive proper guidance on what to watch for before you begin treatment.

  • Common: headache, flushing, indigestion, nasal stuffiness, dizziness, back pain.
  • Less common: visual disturbances (blue-tinge, blurred vision), sensitivity to light.
  • Serious (seek immediate help): chest pain, priapism, sudden vision or hearing loss, fainting.
  • All of the above can and should be reported via the Yellow Card scheme.

What Happens After You Submit Your Yellow Card Report?

Many people wonder whether their report actually makes any difference or simply disappears into a database never to be read again. The reality is quite the opposite. Every Yellow Card report is logged, assessed, and incorporated into the MHRA's ongoing pharmacovigilance analysis. Trained pharmacovigilance specialists review incoming reports and look for patterns — for instance, a sudden rise in reports of a particular side effect with a specific product batch, or an unexpected interaction with another widely used medication. These patterns can trigger regulatory action, ranging from updating prescribing guidance to issuing a Direct Healthcare Professional Communication (DHPC) or adding new warnings to a drug's product licence.

The MHRA publishes regular summaries of Yellow Card data for many product categories, which are publicly accessible and used by researchers, healthcare professionals, and policymakers. Your report, combined with thousands of others, helps build what regulators call the "signal" — the statistical evidence that something is happening beyond background noise. For ED medications specifically, real-world reporting has historically contributed to clearer cardiovascular contraindication warnings, more specific guidance on drug interactions (particularly with nitrates), and improved patient information on the risk of vision-related side effects. Your voice, even as one individual, is part of a system that protects public health on a national scale.

  • Reports are reviewed by MHRA pharmacovigilance specialists.
  • The MHRA may contact you for further information — this is normal and not alarming.
  • Aggregated data is published and shared with the European Medicines Agency (EMA) and the World Health Organisation (WHO) VigiBase.
  • Reports can lead to label updates, new warnings, or prescribing guidance changes.

Overcoming Common Barriers to Reporting ED Side Effects

Despite the simplicity and importance of the Yellow Card scheme, reporting rates among patients remain lower than they could be. This is particularly true for men taking ED medications, where embarrassment, stigma, and the assumption that side effects are "just normal" or "not serious enough" can prevent people from coming forward. It is worth addressing these barriers directly, because they are based on misconceptions that the MHRA and healthcare professionals are keen to dispel.

First and foremost, there is absolutely no shame in taking medication for erectile dysfunction. It is a recognised medical condition affecting an estimated 4.3 million men in the UK, and the treatments available through regulated pharmacies are clinically proven, licensed, and safe when used correctly. If you experienced a side effect — whether mild or severe — your report is just as valuable as one submitted by a consultant urologist. You are not wasting the MHRA's time. Secondly, many men worry that submitting a report will affect their ability to get the medication in future, or that it might be shared with their GP without permission. This is not the case. Reports are treated as confidential, and the MHRA does not share identifiable information with prescribers or insurers. Finally, some men delay reporting because they are unsure whether the medicine actually caused the problem. The Yellow Card scheme explicitly welcomes reports based on suspicion — the word "suspected" is built into the system's name. If you think it might be related, report it.

  • Stigma around ED should never be a barrier to reporting a health concern.
  • Your report remains confidential and will not affect future prescriptions.
  • Suspicion is enough — you do not need a confirmed causal link.
  • Reports from non-healthcare professionals are equally valued by the MHRA.
  • Mild side effects are worth reporting, especially if they are persistent or affect your quality of life.

ED Medication Side Effect Reference Table

Medication Common Side Effects Less Common Side Effects Serious Side Effects (Seek Help Immediately) Report via Yellow Card?
Sildenafil (Viagra / Viagra Connect) Headache, flushing, nasal congestion, indigestion Visual disturbances, dizziness, back pain Priapism, sudden vision loss, severe hypotension, chest pain Yes — all suspected reactions
Tadalafil (Cialis) Headache, back pain, muscle aches, flushing Nasal congestion, indigestion, dizziness Priapism, sudden hearing loss, sudden vision loss, severe chest pain Yes — all suspected reactions
Vardenafil (Levitra) Headache, flushing, nasal congestion Visual disturbances, QT prolongation (rare) Priapism, arrhythmia, severe hypotension Yes — all suspected reactions
Avanafil (Spedra) Headache, flushing, nasal congestion Dizziness, back pain, indigestion Priapism, cardiovascular events, sudden vision or hearing changes Yes — all suspected reactions
Unlicensed / Herbal ED Products Variable and unpredictable May contain undisclosed PDE5 inhibitors Potentially dangerous — especially with nitrates or heart conditions Yes — especially important to report

Key Takeaways

  • The Yellow Card scheme is the UK's official mechanism for reporting suspected medication side effects, including those from ED treatments, and is managed by the MHRA.
  • All major ED medications — sildenafil, tadalafil, vardenafil, and avanafil — can be reported, as can unlicensed or herbal products.
  • Reporting takes under 15 minutes online and does not require a GP reference or confirmed diagnosis, only a reasonable suspicion.
  • Serious side effects such as priapism, sudden vision loss, or chest pain require immediate medical attention first, followed by a Yellow Card report.
  • Your report is confidential, genuinely reviewed by MHRA specialists, and contributes to the national pharmacovigilance system that keeps everyone safer in 2026 and beyond.

When to Seek Professional Advice

While the Yellow Card scheme is designed for reporting purposes, it is not a substitute for medical advice. If you are experiencing any side effect from an ED medication that concerns you — however minor — the right first step is always to speak with a qualified healthcare professional. Your pharmacist is an excellent first port of call for mild or moderate reactions, as they have full access to your medication history and can advise you on whether to continue, reduce your dose, or stop taking the medication altogether. GPs can investigate more complex reactions and refer you to a specialist if necessary.

You should seek urgent medical attention — call 999 or go to A&E — if you experience chest pain, a sudden severe drop in blood pressure, a prolonged erection lasting more than four hours, sudden loss of vision in one or both eyes, or sudden hearing loss. These are medical emergencies. Do not wait to see if they resolve on their own. Once you have received appropriate care, please also submit a Yellow Card report, as these serious reactions are especially important for national safety monitoring. If you are unsure whether your current erectile dysfunction medication is right for your health profile, speaking to a prescribing pharmacist at a regulated online pharmacy is a fast, confidential, and convenient option that many men across the UK are choosing in 2026.

Scientific References

  1. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card: Reporting Suspected Side Effects. Gov.uk. 2024.
  2. NHS. Sildenafil (Viagra) – Side Effects. NHS.uk. 2023.
  3. British National Formulary (BNF). Sildenafil — Interactions, Cautions and Side Effects. NICE BNF. 2024.

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Frequently Asked Questions

How long does a Yellow Card report take to submit?

Submitting a Yellow Card report typically takes around 10 to 15 minutes. The online form on the MHRA Yellow Card website guides you through each step, asking about the medication, the side effect experienced, and your personal details, making the process as straightforward as possible for patients and carers.

Is it safe to continue taking my ED medication after a side effect?

Whether it is safe to continue taking your ED medication after a side effect depends on the severity and type of reaction you experienced. Minor effects such as flushing or mild headaches may not require stopping treatment, but any serious or unexpected reaction should be discussed with a pharmacist or GP before continuing.

Can you report a side effect on behalf of someone else using the Yellow Card scheme?

Yes, you can report a side effect on behalf of someone else using the Yellow Card scheme. The MHRA accepts reports from carers, family members, and healthcare professionals on behalf of the person who experienced the reaction, and you do not need the patient's GP reference number to submit a report.

What is the difference between a common and a serious side effect of ED medication?

The difference between a common and serious side effect of ED medication lies in severity and medical risk. Common side effects such as flushing, headache, or nasal congestion are generally mild and temporary, whereas serious side effects include sudden vision loss, chest pain, or a prolonged erection lasting over four hours, which require urgent medical attention.

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