Kimmy Meinecke blamed herself when she stopped losing weight. For two years, she had been taking a weekly injection of Ozempic to control her diabetes. The medication curbed her appetite so much that sometimes all she ate for dinner was a yogurt or cheese and crackers. But then one day, the scale hit 240 — 25 pounds below the weight at which she had started — and stayed there.

She was thrilled that her blood sugar levels had come down, an outcome worth the side effects she experienced, including nausea and occasional bouts of vertigo. Still, Meinecke, a pastor in Spokane, Washington, had expected to lose more weight and to keep losing it for longer.

Her doctor, however, was not surprised to see her plateau. It’s a point everyone taking medications such as Ozempic, Wegovy and Mounjaro will hit.

“If you think about it, that’s a good thing,” said Dr. Robert Gabbay, chief scientific and medical officer of the American Diabetes Association. “It would be dangerous if you just kept losing weight.”

But doctors say some people seek these drugs to lose as much weight as possible — and are dismayed and disillusioned when they stop. Some go off the drugs after they hit their plateau. When they do, they tend to regain the weight they lost.

“This is not the magic drug that folks like to tout that it is,” Meinecke, 52, said.

Why do people hit weight-loss plateaus?

The human body is built to fight back against weight loss. Smaller bodies usually require less energy, so metabolisms react by slowing down as pounds come off. These changes reduce how many calories someone burns each day, said Dr. Scott Hagan, an assistant professor of medicine at the University of Washington who has studied obesity; losing weight “turns down the thermostat.” This is one reason many people regain some weight even after bariatric surgery or during intense calorie restriction.

Medications such as Ozempic mimic a naturally occurring hormone and slow the emptying of the stomach, so that we feel fuller, faster and for longer. They also target the areas of the brain that regulate appetite, curbing cravings. But there are still open questions about exactly how they work, and that extends to why some people hit a set point at one weight or another.

Another wrinkle is that not everyone responds to these kinds of medications in the same way. In clinical trials of semaglutide, the compound in Ozempic and Wegovy, people with diabetes have tended to lose less weight, less quickly, than people who did not have the condition, Hagan said. A small proportion of those who take these drugs won’t lose weight at all, he added.

When medication meets unrealistic expectations

Dr. Andrew Kraftson, a clinical associate professor in the division of metabolism, endocrinology and diabetes at Michigan Medicine, said most people taking these medications will hit a plateau around 18 months after starting treatment.

Patients often come in with unrealistic expectations, he added, leading to “tough conversations.” Some come to him after they hit their plateau, believing that the medicine wasn’t working. “It’s not all weight loss all the time,” he said.

But Kraftson pointed out that even if someone is still technically classified as overweight, their blood pressure and cholesterol could be under control, and their blood sugar might have dipped because they were taking medication.

“I don’t try to come across as the dream killer, but sometimes you really wonder, what is the hole we’re trying to fill?” he said, adding: “And will additional weight loss really fill it?”

Working to fight the plateau

Gary Czaplewski’s weight plateaued roughly six months after he started taking Wegovy in November 2022. Since then, the private detective in Milwaukee has often wondered if the challenges were worth the benefits of taking the medication.

Czaplewski, 49, has lost about 35 pounds, but he experienced stabbing pains when he first increased his dose — pain so intense that he went back to the weight-loss clinic where he received his shots in a panic that he might have pancreatitis. The treatment costs him $600 a month, which he pays out of pocket, but he no longer craves foods such as custard.

He has tried increasing his exercise to take more weight off. “It’s been more work than I expected,” he said. “I thought I would lose weight easier, longer.”

When patients aren’t satisfied with their weight loss, doctors are left with few options, Kraftson said. They can try to layer in an additional medication, but that might introduce a new cluster of side effects and interactions. They can urge patients to further restrict their food intake and to exercise more, but that can usher in disordered eating behaviors, he said, and be a challenge for those who eat so little to begin with while on these medications.

“You could tell someone that they’re going to lose 15 percent of their weight, potentially, on Ozempic or Wegovy,” he said. “But once they get to 15 percent, it is not like they’re like, ‘Oh, now I’m satisfied, great.’ ”

Blum writes for The New York Times.