In recent years, weight loss injections like Ozempic, Wegovy, and Mounjaro have been hailed as game-changers in the battle against obesity.
Social media is full of glowing testimonials and dramatic before-and-after pictures.
But according to a brand-new study from Cleveland Clinic, the real-life results aren’t quite as impressive as what the pharmaceutical companies promised in clinical trials.
A Major Study Puts the Spotlight on Real-World Weight Loss
Researchers at the Cleveland Clinic took a deep dive into the health records of nearly 8,000 obese American adults who were prescribed either semaglutide or tirzepatide—the active ingredients in these blockbuster weight-loss drugs.
The goal? To find out how much weight people were actually losing outside of the highly controlled environment of clinical trials.
Turns out, patients lost up to 50 percent less weight in the real world than what was advertised in those original studies.
Many People Quit the Drugs Early
Another striking discovery: about one in five people stopped taking the drug within three months, and nearly a third stopped within a year.
That’s a sharp contrast to clinical trial data, where the dropout rate was around 17 percent.
So, why are so many people calling it quits early? The reasons ranged from intense side effects—think stomach paralysis and even reports of vision loss—to high drug costs, poor insurance coverage, and supply shortages.
The Numbers Tell a Different Story Than the Ads
Patients in this real-world study lost between 4 and 12 percent of their body weight in a year, depending on how long they stuck with the treatment.
Meanwhile, clinical trials reported weight loss ranging from 15 to 21 percent after one year.
There was also a huge difference in dosage. About 80 percent of people were on lower maintenance doses than the ones used in trials.
And dosage matters—a lot. Those who stayed on the drugs and took the full recommended doses lost more weight: 14 percent with semaglutide and 18 percent with tirzepatide.
Who Was in the Study?
Most of the participants were middle-aged women with severe obesity (the average BMI was 39, well over the obesity threshold of 30).
About 1,320 of them had prediabetes, a condition that affects an estimated 100 million Americans—many of whom don’t even know they have it.
The study pulled health records from 2021 to 2023 and was recently published in the medical journal Obesity.
Early Quitters Lost the Least Weight
Not surprisingly, the people who stopped taking the medication early saw the smallest changes. On average, they lost about 4 percent of their body weight.
Those who made it to the end of the year without quitting saw better—but still more modest—results than the trials claimed.
Even those who stayed on the meds all year and followed dosage instructions closely didn’t quite hit the top-end weight loss seen in clinical trials.
That difference, researchers say, is likely due to lower commitment levels in real life and people not taking the ideal dose consistently.
Expert Says Real-World Expectations Need a Reset
Dr. Hamlet Gasoyan, the lead researcher behind the study, says these findings are crucial for both doctors and patients.
In the real world, people aren’t achieving the same results you see in tightly controlled clinical trials,” he explained.
The study shows that dosage levels and sticking with the treatment play a massive role in how effective these medications really are.
And with so many people discontinuing due to side effects, access, and affordability, it raises serious questions about how sustainable these drugs are for long-term use.
Popularity Is Soaring, But So Are Dropout Rates
Despite the drawbacks, these drugs are more popular than ever.
Use of GLP-1 drugs like Ozempic and Wegovy has jumped by 600 percent since 2019.
About one in eight Americans has reportedly tried them at some point.
Still, the Cleveland Clinic’s findings are a wake-up call that real-world results may not always match the hype.
As interest in weight loss injections continues to grow, experts are urging people to consider not just the promise of the product—but the practical realities that come with it.