A painkiller found in almost every British medicine cabinet could be quietly damaging people’s livers, a leading pharmacist has warned.
Paracetamol—used by millions daily to treat everything from headaches to fevers—is safe when taken correctly.
But even slightly exceeding the recommended dose can cause permanent liver damage, says Dipar Kamdar, a pharmacist and fellow at Kingston University.
‘While generally safe when used as directed, taking too much—even slightly—can be extremely dangerous for your liver,’ she wrote this week in The Conversation.
‘Even small overdoses, or combining paracetamol with alcohol, can increase the risk of serious harm.
‘Always stick to the recommended dose and speak to a doctor if you find yourself needing pain relief regularly.’
She explained that the danger comes from how the liver processes paracetamol. As it breaks down the drug, it produces a toxic by-product called NAPQI.
Normally, this is neutralised by a protective substance in the body known as glutathione.
Over the counter painkillers, like paracetamol, are used by millions of Britons everyday to deal with headaches, muscle pain, or fevers—but can cause permanent damage to the liver

But in high doses, the liver can become overwhelmed—leading to potentially life-threatening damage.
‘However, in an overdose, glutathione stores become depleted, allowing NAPQI to accumulate and attack liver cells. This can result in acute liver failure, which can be fatal.’
There is growing concern about the spiralling number of cases of liver disease.
Diagnoses have surged by 40 per cent and deaths caused by liver disease have risen four-fold in the past two decades.
Around 10,000 people a year die from it, with those aged 45 to 64 making up half.
The British Liver Trust says 90 per cent of these can be prevented by lifestyle changes.
There are two types of liver disease: alcoholic fatty liver disease and metabolic dysfunction-associated steatotic liver disease (formerly non-alcoholic fatty liver disease).
Excess fat build-up in the liver can cause the organ to become inflamed.
Over time, this may lead to scarring that limits liver function. Left untreated, it can result in end-stage liver disease, also known as cirrhosis.
Liver disease often presents with few or no symptoms in its early stages, but as it progresses can cause fatigue, jaundice, abdominal pain and swelling in the legs and ankles.
The liver filters toxins, produces clotting factors and regulates blood flow. When it fails, complications follow, which can result in death.
The British Liver Trust estimates that 80 per cent of people living with metabolic dysfunction-associated steatotic liver disease are going undiagnosed—with as many as one in three suffering from some form of the condition.
The pharmacist also warns that poor diet and unhealthy eating habits is a key contributor to metabolic dysfunction-associated steatotic liver disease.
She advises against foods high in saturated fat, such as red meat, fried foods and processed snacks.
While suggesting that ‘diets rich in vegetables, fruit, whole grains, legumes, and fish may reduce liver fat and improve related risk factors such as high blood sugar and cholesterol.
Other risk factors include lack of exercise, smoking and drinking alcohol.
Mrs Kamdar says: ‘The liver is a remarkably robust organ – but it isn’t invincible. You can protect it by drinking alcohol in moderation, quitting smoking, taking medications responsibly, eating a balanced diet, staying active and keeping hydrated.
‘If you notice any symptoms that may suggest liver trouble, such as ongoing fatigue, nausea, or jaundice, don’t delay speaking to your doctor. The earlier liver problems are detected, the better the chance of successful treatment.’