GLP-1 overdoses hit 25,000 a year as weight-loss drug use surges

Why do people overdose on GLP-1s?

"I've seen people overdose on a whole load of bizarre things," says Martin Whyte, professor of metabolic medicine at the University of Surrey, including everyday medications like paracetamol and aspirin. With 12 per cent of Americans reported to have used GLP-1s, more use statistically means more mistakes — a pattern also documented in France, Belgium and Australia.

Many errors stem from simple confusion. "You have one box a month, and [patients] have it at home," Whyte explains. Impatience or a forgotten dose the day before can push someone into overdose territory, especially early in treatment when dosages are stepped up gradually.

Who is most at risk?

GLP-1s work by boosting hormones linked to appetite suppression. A massive early dose can trigger a "starvation effect," says Roy Taylor, emeritus professor of medicine and metabolism at Newcastle University. "Starvation is something that the human race has evolved to recover from," he says, "so it's not a disaster. But it may produce short-term ill health" — difficulty eating enough to maintain protein balance.

Diabetic patients on long-term GLP-1s face extra hazards. Combined with insulin, Whyte says, "that's going to have potentially quite a dramatic effect on their insulin or glucose levels," with hypoglycaemia a secondary risk after vomiting and diarrhoea. Patients with eating disorders such as bulimia, now being treated with GLP-1s in experimental trials, may also be vulnerable. "Whether or not they're going to be more prone to an overdose situation, only time will tell," Whyte says.

How did the shortage make it worse?

In 2022, the FDA placed semaglutide and tirzepatide — the active ingredients in Ozempic and Mounjaro — on its drug shortage list. That allowed state-licensed pharmacies and clinicians to compound legal copies, sold in vials and syringes rather than pre-filled autoinjector pens.

Karleigh McClain told KFF News in May what happened next. After losing 22 kilograms on a branded GLP-1, she lost insurance coverage and switched to a compounded version from a telehealth company. Advised to inject nine times the normal dose, she was hospitalised with diarrhoea and vomiting.

The FDA has now proposed withdrawing semaglutide, tirzepatide and liraglutide from its '503B bulks list', cutting large outsourcing companies — and telehealth firms — off from bulk compounding. It has also sent 30 warning letters over prescribing practices. Pharmacies can still compound for now, but as one industry watcher put it: "The legal pathways for compounding these GLP-1 medications are narrowing across the board."

Do the new pills change the risk?

The FDA approved Novo Nordisk's Wegovy pill — the first oral GLP-1 for weight management — in December 2025, and it launched in the US in early January 2026. The UK's regulator approved it in June as prescription-only, though it's not available on the NHS. PwC predicts a 250 per cent increase in weight-loss medication use as a result.

Pills remove what Whyte calls a "structural brake to overdose." With autoinjector pens, one click delivers one dose, then the pen is discarded. Blister packs in a medicine cabinet carry no such limit. Whether that translates into a fresh wave of dosing errors is exactly the kind of unknown that currently worries doctors.