A health expert from the World Health Organization (WHO) is urging anyone taking medication to report side effects, however mild, saying patients hold "the power" to improve medicine safety.
Most medications carry some side effects, ranging from common problems that affect more than one in 10 people to rare or severe adverse reactions that affect fewer than one in 10,000 people. The common issues are often very mild and can include nausea, drowsiness, fatigue, or mild headaches. Some of the rare problems, however, can be serious and include major effects on the body's organs or severe allergic reactions.
While serious reactions are usually reported to the authorities, many people put up with mild ones, thinking it is not worth acting on.
WHO warning on X
Posting on X on Monday, the WHO urged people to take action even if their reaction is mild. Dr Shanti Pal, of the WHO Regulation and Safety Unit, warned that even just not feeling "right" might be related to medication.
She asked: "Ever taken a medicine and felt off, a symptom you weren't expecting? A rash, an upset stomach, unusual tiredness, something that just didn't feel right. These could be signs of a side effect. Don't ignore it. Report it."
She said the information could prove vital and make a difference to others in the future. She explained: "Medicines can improve health and save lives every day, but sometimes they can cause side effects. That's why reporting matters. That list of side effects in your medicine leaflet it exists because people like you spoke up."
Why reporting matters
"Reports from patients and healthcare professionals help us know our medicines better. Every symptom you report becomes real-world evidence, a picture of how a medicine actually works, not in a lab, but in real life for real people," she said.
"When you report a side effect, you're doing more than sharing your story. You're giving experts a valuable piece of the puzzle. When combined with other reports, it can help those very experts identify potential safety issues, and timely action can be taken to keep patients safe.
"That's the power in your hands. So, if you experience a side effect, talk to a healthcare professional and report it through your national reporting system. Because your voice can help make medicine safer and help protect others, maybe even someone you know or love."
Yellow Card scheme in the UK
In the UK, people should report any side effects (Adverse Drug Reactions or ADRs) through the Yellow Card reporting scheme run by the Medicines and Healthcare products Regulatory Agency (MHRA), the organisation which regulates medicines, medical devices, blood components, e-cigarettes, and herbal or homeopathic remedies across the country.
The MHRA advised: "Your Yellow Card report plays a key part in keeping others safe. Your experience can ensure that all healthcare products can continue their positive impact on peoples' lives, by helping the MHRA identify new safety issues as early as possible."
The MHRA is running a campaign throughout the week of November 2-8 urging people to tell them of side effects. Its key message was: "Side effects - don't ignore them, report them." It added: "There are many different types of side effects and if you think you're experiencing a side effect, do not suffer in silence – report it."
What to report and how
The MHRA advised: "For established medicines and vaccines you should report all serious suspected ADRs, even if the effect is well recognised." It said it was particularly interested in receiving Yellow Card reports of suspected ADRs in children, in patients over 65, to biological medicines and vaccines, associated with delayed drug effects and interactions, and to complementary remedies such as homeopathic and herbal products.
You can report an issue with a medicine, device, vaccine, herbal or homeopathic remedy via the Yellow Card scheme, electronically through the Yellow Card website or the free Yellow Card app, available from the Apple App Store or Google Play Store. For patients without online access, the scheme can be contacted free on 0800 731 6789, Monday to Friday between 9am and 5pm.
Adverse incidents involving medical devices should be reported in England, Wales and Northern Ireland using the Yellow Card scheme in accordance with organisational medical device policies and procedures, and in Scotland to the Health Facilities Scotland online incident reporting system, unless it is a private facility providing care to private clients, in which case reports go to the MHRA and the Care Inspectorate. The Yellow Card website should also be used to report suspected problems involving defective medicines, falsified products (fake medicines or devices), and safety concerns associated with e-cigarettes or their refill containers.
