Wegovy, also used by Elon Musk: How does it compare with Saxenda, and what are its effects and side effects?

There is intense interest in Wegovy, the obesity medication Elon Musk mentioned as his weight-loss secret. Developed by Danish pharmaceutical company Novo Nordisk to treat overweight and obesity, Wegovy is a GLP-1 (glucagon-like peptide-1) analogue injected subcutaneously once a week, with semaglutide as its main ingredient.

Wegovy stimulates pancreatic beta cells to promote insulin secretion and slows gastric emptying, increasing fullness. It thereby suppresses appetite, reduces food intake and induces weight loss. In a multinational clinical trial, the Wegovy group lost an average of 14.9% of body weight. Another advantage over existing oral obesity medicines is the convenience of a once-weekly injection.

Existing prescription weight-loss drugs include phentermine, phendimetrazine and orlistat. Phentermine and phendimetrazine are appetite suppressants acting on the central nervous system, but may cause insomnia, palpitations or increased blood pressure. Orlistat inhibits fat-digesting enzymes to block absorption of dietary fat. Gastrointestinal effects such as fatty stools and abdominal discomfort can occur, and caution is needed because it can interfere with fat-soluble vitamin absorption. Unlike these drugs, Wegovy works through a different mechanism as a GLP-1 analogue and produces relatively high weight loss. Nevertheless, it too may cause side effects, so obtaining a prescription after thorough consultation with a doctor is important.

Saxenda is another GLP-1 analogue like Wegovy; both have semaglutide as their main ingredient, but differ in dose and approved uses. Saxenda was developed to treat diabetes, but is also used for obesity after its weight-loss effects were identified. Wegovy was developed for obesity from the outset and contains a higher dose of semaglutide than Saxenda. Greater weight loss can therefore be expected, but the risk of side effects may also be higher. For both medicines, an appropriate dose and regimen must be decided after consulting a doctor.

Attention is also needed to potential adverse effects of Wegovy. Common gastrointestinal effects include nausea, vomiting, diarrhoea and constipation. Because it lowers blood glucose, patients with hypoglycaemia should avoid it. Rare but serious effects, including pancreatitis, gallbladder disease and reduced kidney function, have also been reported.

Wegovy may provide effective weight loss, but is not suitable for everyone. A doctor must prescribe the dose and regimen appropriate to the individual, and any side effects should be reported immediately so suitable action can be taken. In particular, underlying diseases or other medications should be described in detail to minimise risks such as drug interactions.

Wegovy is a prescription medicine, not simply a diet supplement. It should therefore be used under medical guidance for safe, effective weight management. A healthy diet and regular exercise alongside it are also important. Rather than impatience for weight loss, maintaining healthy habits with a long-term perspective is preferable.