Enlarge / Wegovy is an injectable prescription weight-loss medicine that has helped people with obesity. (credit: Getty | Michael Siluk)

A large, long-term trial of the weight-loss medication Wegovy (semaglutide) found that people tended to lose weight over the first 65 weeks on the drug—about one year and three months—but then hit a plateau or "set point." But that early weight loss was generally maintained for up to four years while people continued taking the weekly injections.

The findings, published Monday in Nature Medicine, come from a fresh analysis of data from the SELECT trial, which was designed to look at the drug's effects on cardiovascular health. The trial—a multicenter, double-blind, randomized, placebo-controlled trial—specifically enrolled people with existing cardiovascular disease who also were overweight or obese but did not have diabetes. In all, the trial included 17,604 people from 41 countries. Seventy-two percent of them were male, 84 percent were white, and the average age was about 62 years old.

Last year, researchers published the trial's primary results, which showed that semaglutide reduced participants' risk of heart attack, stroke, and cardiovascular-related deaths by 20 percent over the span of a little over three years.