Unfortunately people gain the weight back once they stop taking the drug if there is no lifestyle change which there often is not. A guy I know owned a good chunk of Sequence which essentially fast tracked access to Wegovy through telehealth and working with insurance companies. He was pushing to partner with a company that could provide that lifestyle change info so that people could keep off the weight when they stop using it. Weight Watchers bought them so hopefully they can help provide that lifestyle change.
So far the side effects of Wegovy are fairly standard but it has only been around for 10 years and widely studied for an even shorter period since it has only been on the market for a couple years.