NHS England’s medical director says he is alarmed by reports that people are using weight-loss drugs as “a quick fix” to lose a few pounds and get “beach-body ready” this summer.

Professor Stephen Powis said the side-effects of the drugs could be dangerous, and they needed to be used under medical supervision.

Interest in Wegovy, for treating obesity, surged after studies suggested users could lose over 10% of their body weight.

Drug treatments are now seen as an important tool in tackling obesity.

Wegovy, a weight-loss injection, has been approved for use on the NHS in England for those who are most obese, but supplies of the drug are limited. It contains the drug semaglutide, which makes people feel full and reduces their appetite.

An anti-obesity drug called Mounjaro could be recommended for NHS use soon.

Another injection, Ozempic, also contains semaglutide but is designed to treat type 2 diabetes. It has not been approved for helping people who are obese to lose weight – yet there is huge demand for the medication, creating a shortage for diabetes patients.

Many online pharmacies are selling semaglutide injections, but they make few checks on the weight or underlying health of the person buying them.

A recent BBC investigation found an online black market in sales of semaglutide without prescription, which doctors said could put people’s health at risk. The investigation also found the drug being offered in beauty salons in London and Manchester.