Brits have been warned against the use of an anti-obesity pill that is available for general sale without prescription.
Drug safety regulators fear the slimming tablet Alli could lead to numerous disorders, including pancreatitis, kidney stones, liver problems or severe fits in people with epilepsy.
According to new data, there are 31 reported cases of adverse reactions since the pill hit pharmacies in January last year.
Alli (generic name orlistat) was an instant hit with the overweight, who could buy them for just 50pound a month, without a full consultation with their GP.
However, the evidence against the pill has been growing.
The 31 adverse reactions include palpitations, tummy problems and swollen tongues.
Patients who take a common drug for the treatment of thyroid problems are also being told to take a doctor's advice because the medicines could interact badly.
And because diarrhoea is a common side-effect, women have been cautioned the pill could lessen the effectiveness of the contraceptive Pill.
American health watchdogs are looking into any links to liver disease, while European researchers disagree.
The Medicines and Healthcare Regulatory Authority in the UK is now insisting that new warnings are added to packets of Alli after a review by the EU Committee for Medicinal Products for Human Use.
However the manufacturers of Alli say the drug has been well tested for safe consumption.
"The update to the label for Alli expands the information available to consumers and healthcare professionals to help facilitate product use," the Daily Express quoted manufacturers, GlaxoSmithKline, as saying.
They added: "Consumers can be reassured that orlistat, the active ingredient in Alli, is the most studied weight-loss medicine, with a safety profile established through 100 clinical studies with over 30,000 patients."