Semaglutide Bests Liraglutide in Long-Term Weight Loss

Patients with obesity or type 2 diabetes (T2D) who stuck with their medication for a year lost more weight with semaglutide than with liraglutide, a new study reported.

Researchers at the Cleveland Clinic reviewed records for 3389 adult patients with obesity who were prescribed one of the glucagon-like peptide 1 (GLP-1) medications for either T2D or obesity between 2015 and 2022. They found that patients who took either semaglutide or liraglutide for obesity were more likely to lose weight than those prescribed the medications for T2D and that semaglutide was associated with greater weight loss.

The study, published in JAMA Network Open, identified “key characteristics that could inform the probability of achieving sustained weight loss of a magnitude large enough to provide clinically significant health benefits,” said lead author Hamlet Gasoyan, PhD, a staff investigator at the Center for Value-Based Care Research in the Department of Internal Medicine of Primary Care Institute, Cleveland Clinic, Cleveland.

Only about 40% of patients continued to take the medications at 1 year. Those who did not continue did not achieve the same level of weight loss, Gasoyan told Medscape Medical News. He and his colleagues will study the factors that lead patients to stop taking the medications in a future paper.

The results from the current paper give patients and clinicians reasonable expectations on the trajectory of weight loss when the drugs are prescribed for diabetes vs obesity, said Gasoyan, an assistant professor of medicine at Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland.

Semaglutide Superior

Because of the study’s timeframe, the majority of GLP-1s were prescribed for T2D. Liraglutide was approved (as Saxenda) for obesity in December 2020 and semaglutide (as Wegovy) for obesity in June 2021.

The authors were able to capture fills under the brand names and doses approved by the US Food and Drug Administration for obesity (Wegovy, 1.7 or 2.4 mg; Saxenda, 3.0 mg), as well as those approved for T2D (Ozempic, 0.5, 1.0, or 2.0 mg; Victoza, 1.2 or 1.8 mg).

The researchers reported that among the 3389 patients, 1341 (39.6%) were prescribed semaglutide and 1444 (42.6%) were prescribed liraglutide for T2D. For obesity, 227 (6.7%) were prescribed liraglutide, and 377 (11.1%) were prescribed semaglutide.

Overall, those with diabetes had a −3.2% mean weight change compared with those with obesity who had a −5.9% mean weight change.

Semaglutide consistently outperformed liraglutide, particularly in obesity.

Overall, at 1 year, the mean percentage weight change among those with obesity was −5.1% with semaglutide compared with −2.2% with liraglutide (P 

At 1 year, among those with obesity who were persistent in semaglutide use (defined as 90-275 medication days) had a mean body weight of −12.9% vs −5.6% in those taking liraglutide.

Overall, about 40% of patients were persistent at 1 year. But the figure was higher for semaglutide (45.8%) and lower for liraglutide (35.6%).

Liraglutide requires daily injections compared with semaglutide that requires weekly injections. The authors did not study the reasons for medication adherence or discontinuation.

Key factors for achieving a greater than 10% weight loss — considered clinically meaningful — included taking semaglutide, receiving a GLP-1 for obesity, persistent medication use, high dosage, and being female.

Real-World Data Welcomed

Michael Weintraub, MD, an obesity medicine specialist and clinical assistant professor at NYU Langone Health, New York City, said that having real-world data on GLP-1 effectiveness has been much needed.

The researchers “did a really good job at stratifying these patients,” he told Medscape Medical News, adding that the study “adds to the literature in terms of what we might expect and what things we should look out for when we want to obtain the maximum degree of weight loss and attain overall better metabolic health for our patients.”

One strength: The researchers were able to capture when someone actually filled a prescription, he said. Clinicians don’t always know whether a prescription for a GLP-1 has been filled because patients might go without the drug because of insurance hurdles or supply issues, he said.

Weintraub was not surprised that the study showed that both GLP-1s produced more weight loss in those with obesity than in those with T2D, as that has become a common finding. No one has been able to explain why there is such a difference, said Weintraub. “As a field, we actually don’t know the reason behind that yet,” he said.

Given the small number of patients prescribed semaglutide for obesity, that “limits the generalizability,” he said.

Even so, semaglutide is increasingly proving superior, Weintraub said. “I would reach towards semaglutide every time either for individuals with type 2 diabetes or individuals with obesity,” he said. “The major limitation, though, is insurance coverage rather than, unfortunately, my clinical decision-making.”

He also still sees a role for liraglutide. It will go off patent soon and that could “lead to a lower price point and hopefully greater access for patients,” Weintraub said.

Gasoyan and Weintraub reported no relevant financial relationships. Co-author W. Scott Butsch, MD, reported receiving advisory board fees from Novo Nordisk A/S and research funding from Eli Lilly during the conduct of the study.

Alicia Ault is a Saint Petersburg, Florida-based freelance journalist whose work has appeared in publications including JAMA and Smithsonian.com. You can find her on X: @aliciaault.