How do weight-loss drugs like Mounjaro and Wegovy work?

How do weight-loss drugs like Mounjaro and Wegovy work?Just nowShareSaveAdd as preferred on GoogleNick Triggle and Philippa RoxbyBBC NewsGettyIt is thought about 1.6 million people are on weight-loss drugs in the UK.Some patients are able to get the injections through the NHS but most buy them privately. The most popular jabs are called Mounjaro and Wegovy.The jabs are highly effective, but experts warn that users should be aware of the risk of weight gain once they stop taking the drugs. How do Wegovy and Mounjaro work?There are many drugs on the market for weight loss, which can be in the form of an injectable pen or a capsule.Weight-loss injections which can be prescribed by the NHS are:semaglutide, marketed under the brand name Wegovytirzepatide, sold as Mounjaroliraglutide, sold as SaxendaThe drugs are given as weekly injections via pre-filled pens that can be self-administered into the upper arm, thigh or stomach.They work as an appetite suppressant by mimicking a hormone called GLP-1 which makes people feel fuller. Mounjaro also affects metabolism and helps regulate energy balance.The jabs might work better for some people than for others. Experts are starting to understand how different factors, such as genetics, might be involved. Patients generally start on a low level dose which is gradually increased until they reach a maintenance dose. The NHS recommends the jabs for people who are overweight with obesity-related health risks, not people who just want to get a bit thinner.The jabs are always prescribed alongside healthier eating and exercise programmes.How much weight do people lose while taking weight-loss drugs? Getty ImagesPeople typically start to lose weight within a few weeks. The first head-to-head trial of Mounjaro and Wegovy found that the former was more effective. Mounjaro's 20% weight reduction, after 72 weeks of treatment, exceeded the 14% for Wegovy.The trial - funded by Mounjaro manufacturer Eli Lilly - involved 750 obese people, wit...