What happens when you stop taking weight-loss injectables? An obesity doctor weighs in

ATLANTA - Weight-loss injectables can help turn down the "food noise" in your head, so obesity physician Dr. Alicia Shelly of the Wellstar Center for Best Health says you are not constantly thinking about food.

"You don't have this feeling, where you wake up, and you're like, ‘What am I going to eat today,’" Shelly says. "You're, like, ‘Let me just eat something healthier than what's just available.’"

Shelly says the medication helps patients cut back on their eating by signaling to their brain that they are full.

The drugs can also slow down "gastric emptying," so that users feel full more quickly.

Doctors are weighing in on what happens when people stop using newly approved weight-loss drugs. (FOX 5)

Yet, most people who start a weight-loss injectable quit using the medication within a year.

What happens when you stop taking a GLP-1?

A Reuters analysis, which looked at pharmacy data from 2021, found only about a third of people who began taking Wegovy or a similar drug were still on it a year later.

Dr. Shelly says her patient who have stopped using the medication have gained back some of the weight they lost on semaglutide and tirzepatide, a new class of medications known as GLP-1 receptor agonists, which were originally developed to treat Type 2 diabetes.

Wegovy is a semaglutide which aims to help slow down "gastric emptying," so that users feel full more quickly.

"When people stop taking the medication, they do have some weight regain," she says. "It's not that they go back to where they started, but they definitely see a difference. And the reason why this occurs is that their appetite comes back. So, they start feeling more hungry, and they don't necessarily have that feeling of feeling full."

A 2022 study published in the JAMA Network in December 2023 found volunteers using tirzepatide, the active ingredient in the new weight-loss drug Zepbound and in the diabetes drug Mounjaro, lost about 20% of their body weight over 72 weeks on the medication.

But those who stopped taking the medication regained 14.8% of their body weight within a year of discontinuing the medication.

What happens when you stop taking semaglutide?

Another study found those who quit using semaglutide, the active ingredient in brand name drugs like Wegovy and Ozempic, regained most of the weight they had lost within a year.

Wegovy and Ozempic are in a new class of medications known as GLP-1 receptor agonists.

Dr. Shelly says the rebound weight gain has landed some of her patients with weight-related health conditions back at square one.

"Not only are they feeling more frustrated and more discouraged, their health outcomes are worsening," Shelly says. "Their cholesterol is getting high, or their blood sugar is getting higher, and their hemoglobin A1C is getting higher."

People may quit using the injectables for many reasons: they lose their insurance or their coverage changes, they experience negative side effects, or their weight-loss plateaus.

How much does Wegovy or Ozempic cost?

Cost is another reason why people stop taking it.

For people paying out of pocket, the injectables can range from just over $1,000 to $1,400 a month, according to the discount drug website GoodRX.com.

Zepbound, which active ingredient is tirzepatide, helps to cut about 20% body fat over 72 weeks, according to studies.

Dr. Shelly says the medications are designed to be used in conjunction with a healthy lifestyle.

So, she encourages patients who stop using the medication to continue to stay active and stick with a healthy, balanced diet. 

"But for some people, they may need to be on this chronically," Dr. Shelly says.  And this is not just with these medications. You actually can see it even with lifestyle changes. When people go on a certain diet or adopt certain lifestyle habits, where they lose weight, and when they stop, it comes back.'"