The number of hospital admissions for bad reactions to weight-loss drugs is more than four times higher than previously thought – with a staggering 274 cases reported on top of nearly 15,000 said to have suffered ill effects.

Last month, the medicines regulator said there had been 68 UK hospitalisations associated with ‘miracle’ weight-loss jabs such as Ozempic, used to treat obesity and diabetes.

But now it has emerged that the figure is far higher at 274, while the number of adverse reactions linked to the drugs has reached an astonishing 14,996, according to the Medicines and Healthcare products Regulatory Agency (MHRA) – more than double the 7,228 reactions reported last month.

The surge in adverse reactions and hospitalisations chiefly involve gastrointestinal side-effects such as nausea, vomiting, constipation and diarrhoea, the watchdog said.

Fresh concerns have been raised over the sale of the jabs online alongside the boom in easily available unlicensed, black market jabs and ‘off-label’ use without prescriptions or expert supervision.

Speaking to The i newspaper, which released the figures, Layla Moran MP, chairman of the Health and Social Care Committee, called for ‘stronger regulation’ of online sales and said it was ‘alarming to hear about the high number of hospitalisations’.

She added: ‘It is concerning that the illicit black-market sale of weight-loss drugs online has flourished, exposing individuals to serious risks from drugs that are unregulated and have not been prescribed to them.

‘These findings suggest that there is a need for stronger regulation on the availability and online sale of weight-loss drugs.’

Some experts downplayed the data as ‘relatively low’ but admitted the number of hospitalisations was ‘concerning’.

Dr Danielle Middleton, MHRA’s deputy director of benefit-risk evaluation, said ‘the benefits still outweighed potential risks when used for the licensed indications’, adding: ‘The decision to start, continue or stop treatments should be made jointly by patients and their doctor, based on full consideration and discussion of the benefits and risks.’

But Katharine Jenner, director of the Obesity Health Alliance, said the MHRA and other regulators ‘need to look at what has happened with these concerning number of hospital admissions’.

She said weight-loss drugs such as semaglutide, sold as Ozempic and Wegovy, and tirzepatide, sold as Mounjaro, were safe if taken ‘under careful supervision’ but feared online pharmacy checks on existing health conditions were not ‘rigorous enough’.