Ozempic Insulin injection pen for diabetics and weight loss
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How much weight a person loses on liraglutide or semaglutide depends on a number of different factors, new research found.
The study found that the type of medication a person takes, the treatment indication, the dosage, and other factors can have an impact on weight loss.
Many of these are out of people’s control, however, experts recommend taking the drug as consistently as possible for better results.
The amount of weight a person loses on medications such as Ozempic and Wegovy varies based on their medical history, how they take the drug, and other factors, a new study finds.1

The researchers found that how much weight a person loses when they’re taking semaglutide (Ozempic, Wegovy) or liraglutide (Victoza, Saxenda) depends on which medication they’re taking, how consistently they take it, the dosage, and whether they’re taking it for type 2 diabetes or obesity.1

Additionally, the data showed that the potential to lose 10% or more of your body weight within a year is higher if you are female, have a higher starting body mass index (BMI), take semaglutide, stay on a high dose, take it for obesity, and take it regularly.

The study was published in JAMA Network Open on September 13.

“Our current work provides clear evidence that persistence is key for achieving clinically meaningful weight loss with these medications at one year,” lead study author Hamlet Gasoyan, PhD, MPH, a researcher at Cleveland Clinic, told Health.

Here’s what experts had to say about why certain factors can impact how much weight you lose on glucagon-like peptide-1 (GLP-1) drugs and how to choose a weight loss drug that works for you.

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Who Sees the Most Significant Weight Loss Results on GLP-1 Drugs?
The two medications included in the new JAMA Network Open study—semaglutide and liraglutide—belong to a class of drugs known as GLP-1 receptor agonists. They’re approved for type 2 diabetes and weight management, depending on the drug name.234

As semaglutide—available under the names Ozempic, Wegovy, and Rybelsus—grows in popularity, there’s been a need for more real-world data on how the drugs are actually working in the people taking them, Robert Kushner, MD, an obesity medicine specialist at the Northwestern University Feinberg School of Medicine, told Health.

For this study, investigators evaluated data on 3,389 adults who started taking either semaglutide or liraglutide between July 2015 and June 2022 at Cleveland Clinic locations in Ohio and Florida. Most were prescribed a GLP-1 drug for type 2 diabetes management, but about 18% were taking either liraglutide or semaglutide for obesity.

The researchers found that one year after taking these medications, study participants lost varying amounts of weight depending on a number of factors.

Participants, on average, lost about 5.1% of their body weight if they were taking semaglutide and 2.2% of their body weight if they were taking liraglutide. Participants who were taking high doses of their GLP-1 drug—1.7 milligrams (mg), 2.0 mg, or 2.4 mg of semaglutide, or 3 mg of liraglutide—lost more weight compared to people taking lower doses.1

The treatment indication mattered, too—for semaglutide specifically, people taking it for obesity lost 12.9% of their body weight, while those taking the medication for type 2 diabetes lost 5.9% of their body weight. Similarly, people on liraglutide lost about 5.6% of their body weight if they were being treated for obesity, as compared to 3.1% if they were being treated for type 2 diabetes.1

Researchers also found that participants were more successful if they had better access to their medications. People with insurance coverage for 90 to 270 days lost 2.8% of their body weight, while people who had less than 90 days of insurance coverage lost just 1.8%. Only about four in 10 participants took their medication persistently in the year after starting it.1

The team also looked closer at the participants who lost 10% or more of their body weight—being female, taking semaglutide, taking the drug for obesity, having a higher BMI, being consistent, and taking a higher dose were all associated with this more significant weight loss.1

This study was well-conducted, Kushner said. However, the study had a relatively small number of participants and involved just one health system, which means the results may not be representative of the entire country, Tricia Rodriguez, PhD, MPH, senior applied scientist at Truveta Research, told Health.

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Why Do Gender, BMI, and Other Factors Influence Weight Loss?
The results of this latest study aren’t necessarily surprising and are “in line with data from clinical trials for the most part,” Eduardo Grunvald, MD, medical director of the weight management program at UC San Diego Health, told Health.

Researchers have previously dug into why these different factors can impact a person’s weight loss while on a GLP-1 drug.

For example, in other GLP-1 drug trials, women have outperformed men in terms of weight loss, Kushner noted.5 Some clinicians believe this is the case because women’s bodies may absorb a greater amount of the medication.

Other predictions are that “women may lose more weight due to hormonal reasons,” Grunvald said. “Some have also theorized that women feel more pressure from society to be lean, so they may have more motivation [for] intense lifestyle changes.”

People with higher BMIs tend to lose more weight, too—it’s also not the first time this has been seen in a trial, Kushner noted. This could be because GLP-1 drugs “profoundly reduce your appetite,” he said, leading to more significant change in people who may have been previously eating more calories.

But the connection between greater weight loss and other factors is harder to nail down.

“No one knows exactly why people with diabetes lose less weight than those without,” Grunvald said.

It could be that people with type 2 diabetes might take lower doses than people being treated for obesity, Kushner said. Being on a diabetes medication can sometimes lead to weight gain, Gasoyan added, or people with the condition may have higher insulin levels, altered microbiota, genetic predispositions, or some other barrier to losing weight.

“That has been a head-scratcher for a long period of time,” Kushner said.

Choosing a Weight Loss Medication
Some of these factors associated with greater weight loss on GLP-1 drugs—including starting BMI, gender, and treatment indication—aren’t necessarily in people’s control. However, taking semaglutide over liraglutide, taking a higher dose, and taking the medication consistently could raise a person’s chance of losing more body weight.1

But if semagluide or liraglutide still aren’t working for you, there are other things you can do.

Rodriguez published a study in July which found that tirzepatide can cause “significantly greater weight loss” as compared to semaglutide, so trying Mounjaro or Zepbound could lead to even better results.6

But one of the most important things that people can do if they want to see weight loss results is to take their GLP-1 drug routinely, Kushner said. Of course, that means that people need to have adequate access to their medication.

“One of the limitations of a real-world study is we do not know why six out of 10 people did not take the medication continuously,” Kushner noted. Shortages and side effects could absolutely play a role, along with steep costs and insurance coverage issues.