Weight Loss and Regain after Starting and Stopping GLP-1 Related Drugs

Several blogs on Knowing Diabetes describe the benefits of GLP-1 related drugs such as semaglutide (marketed as OzempicTM, RybelsusTM, or WegovyTM) and tirzepatide (marketed as MounjaroTM ,or ZepboundTM). Well-done research shows that these drugs improve glucose control, lower blood pressure, and reduce the chance of serious outcomes such as heart attacks and strokes. They also show that most people will lose weight. This blog discusses the average weight loss someone should expect, as well as weight regain if the drug is stopped.

No drug works the same in everybody. Research can only show what happens on average in the average person. The average person with type 2 diabetes loses more weight with higher doses. Therefore, on a low dose of 0.5 mg semaglutide weekly, people with diabetes can expect about a 5% weight loss. On the highest dose of 2 mg per week, they can expect a 7% weight loss. For tirzepatide, people on a low dose of 5 mg per week can expect a weight loss of 8%, while those on the highest dose of 15 mg per week can expect a 12% weight loss. Note that for somebody who weighs 200 pounds (about 90 kg) a 5% weight loss would be equal to about 10 pounds or 4.5 kilograms, and a 10% weight loss would be 20 pounds or 9 kilograms. Most of the weight loss tends to occur by about 8 months after which weight plateaus by about 12 months.

People with diabetes tend to lose much less weight than people without diabetes. The best estimate is about half the weight loss. Reasons for this are not clearly known. However, when these drugs improve diabetes control, this can prevent the weight loss due to high blood sugars. This means that the glucose and other effects of these drugs have opposite effects on weight.

People commonly ask what happens if they stop the drug. This is not well known in people with diabetes. People without diabetes who stop them typically regain about 70-75% of the weight that they lost. Therefore, if a 200-pound person lost 20 pounds they could expect to regain 15 pounds if they stopped the drug. Usually, this weight regain takes about a year. Fortunately, most people do not regain all the weight that they lost. This is not surprising. Stopping a blood pressure drug leads to a rise in blood pressure and stopping a cholesterol drug, leads to a rise in cholesterol. The good news for these drugs is that most people do not regain all of the weight that they lost.

Like any drug, there is no one size fits all. Everybody is different and needs to work with their healthcare team to decide the best plan for them.

About the author

Hertzel Gerstein

Hertzel is an endocrinologist and professor at McMaster University who is in high demand as a speaker, advocate, and educator on diabetes-related topics. His research focuses on using large, international randomized trials to identify and test new ways of preventing type 2 diabetes, reducing serious health outcomes like strokes and death, and achieving type 2 diabetes remissions.