That’s not surprising, says John Wilding, an obesity researcher at the University of Liverpool who led a major investigation on the use of semaglutide for the treatment of overweight or obese adults. “Clinical studies tell us about the biology — whether the drug is working — and it’s a very controlled situation because that’s how the studies are designed,” he says. People usually don’t have to pay for drugs in clinical trials, and they are supported with regular check-ins from research staff.
In the real world, there are all sorts of reasons why people stop using drugs. A survey of diabetic patients asked them — and their doctors — why they stopped taking their GLP-1RA. Patients who stopped the drugs cited side effects such as nausea and diarrhea, a dislike of having to inject themselves regularly, and disappointment that the injections didn’t help them lose weight or control their blood glucose. In the US, nearly half of patients who stopped using a GLP-1 RA cited cost as the reason. We know that patients in the US have higher co-payments less likely to stick with their diabetes medications. “These drugs are extremely expensive, especially the weekly ones,” says William Polonsky, president of the Behavioral Diabetes Institute in California. The list price for a monthly dose of Wegovy is nearly $1,350, though some insurers will cover at least some of that hefty cost.
If these patterns hold true for the drugs as they’re used for weight loss—and that’s still a big “if” at this point—then perhaps we shouldn’t expect everyone who starts using Wegovy or similar drugs to be there forever will stay on. The UK’s National Institute for Health and Care Excellence, which determines which medicines should be available through the National Health Service (NHS), recommends a two-year limit on how long someone can Wegovy be prescribed for weight loss. It’s possible, says Wilding, that some people stop taking the drug after they lose a certain amount of weight and choose to manage their health through diet and exercise.
We already know that when people stop taking semaglutide, they regain most of the weight lost during the treatment. This raises an important question. If people regain their lost weight, will they still be healthier in the long run than someone who has never lost weight in the first place?
For semaglutide, the short answer is we don’t know. But there is some intriguing data that suggests nutritional interventions may have lasting benefits long after they’re scrapped. In 1986, nearly 440 people with prediabetes in the Chinese city of Da Qing were assigned to a trial in which they were encouraged to follow a healthier diet, exercise, or a combination of the two for six years. The control group was asked to continue their lifestyle as usual. Thirty years later, scientists returned to the people who participated in the study and found that those in the diet and exercise groups had diabetes later on and had less cardiovascular disease than people in the control group.