LONDON - A new type of drug is generating excitement among the rich and the beautiful. Just a jab a week, and the weight falls off. Elon Musk swears by it; influencers sing its praises on TikTok; suddenly slimmer Hollywood starlets deny they have taken it. But the latest weight-loss drugs are no mere cosmetic enhancements. Their biggest beneficiaries will be not celebrities in Los Angeles or Miami but billions of ordinary people around the world whose weight has made them unhealthy, writes the Economist.

Treatments for weight loss have long ranged from the well-meaning and ineffective to the downright dodgy. The new class of drugs, called glp-1 receptor agonists, seems actually to work. Semaglutide, developed by Novo Nordisk, a Danish pharmaceutical firm, has been shown in clinical trials to lead to weight loss of about 15%. It is already being sold under the brand name Wegovy in America, Denmark and Norway and will soon be available in other countries; Ozempic, a lower-dose version, is a diabetes drug that is also being used “off label” for weight loss. A rival glp-1 drug, made by Eli Lilly, an American firm, is due to come on sale later this year and is more effective still.

Analysts think the market for glp-1 drugs could reach $150bn by 2031, not far off the market for cancer drugs today. Some think they could become as common as beta blockers or statins.

With so much bad news around, it was a pleasure to run a cheerful cover story this week. Scientists have stumbled upon a weight-loss drug that actually seems to work. Or rather, a class of drugs called GLP-1 receptor agonists, sold under brand names such as Wegovy and Ozempic.

TikTok influencers and Hollywood celebrities are obsessed with the injections, which have led in clinical trials to weight loss of around 15%. Eventually, the beneficiaries will be billions of people whose weight has made them unhealthy. This is no longer just a rich-country problem.

By 2035 more than half the people on the planet will be overweight or obese, by one estimate. For now, the drugs are expensive, and their long-term effects are unknown. But competition—and bulk purchases by governments—will make them cheaper.

And if careful monitoring finds no major side-effects, the drugs could help humanity win its long and hitherto futile fight against flab.