Pharmacist Raj Patel, known as the Straight-Talking Pharmacist on TikTok, has warned metformin users to seek help immediately if they experience severe side effects such as vomiting, dehydration, or signs of a rare complication called lactic acidosis. He also advised against stopping the medication without medical guidance.
Common side effects and when to act
Metformin is used to treat type 2 diabetes and is also prescribed for some people with other conditions, including polycystic ovary syndrome (PCOS). According to the NHS, common side effects include nausea, diarrhoea and stomach pain, particularly when someone first starts taking the medicine.
In a recent video, Mr Patel said: "If you're taking metformin and you're planning your day around the nearest toilet, your medicine could be part of the problem." He explained that these symptoms often settle as the body adjusts, but advised seeking advice if they persist or keep returning.
Managing symptoms and seeking advice
The NHS recommends taking metformin with food and advises speaking to a pharmacist or doctor about side effects that are troublesome or do not go away. Mr Patel suggested that taking each tablet with or just after food can help, and if symptoms continue, asking a healthcare professional whether a dose adjustment or slow-release version might be more suitable.
He also warned against automatically blaming metformin if diarrhoea begins long after treatment has started. Keeping a note of when symptoms began and whether they tend to follow a dose could help a pharmacist or prescriber assess what is happening.
Serious symptoms require urgent care
More serious symptoms need particular care, especially if diarrhoea or vomiting leaves someone unable to keep fluids down. The NHS warns that illness involving vomiting or diarrhoea can lead to dehydration while taking metformin, so people should contact a pharmacist or doctor for advice.
Mr Patel noted: "If you're vomiting, can't keep any food down or fluid while becoming dehydrated, make sure you get help straight away." He also warned that breathing problems, severe weakness or severe stomach pain can signal lactic acidosis, which requires urgent medical attention. Despite the warnings, he urged people not to stop their regular treatment on their own, saying: "Whatever you do, don't stop metformin yourself."
