Semaglutide vs Liraglutide for Weight Loss in Patients With Obesity

vial injection
vial injection
Investigators examined the weight loss effects of semaglutide compared with liraglutide in patients with obesity who do not have diabetes.

Semaglutide provided weight loss benefits when added to dietary and physical activity modifications for individuals with a body mass index above 30 kg/m2, according to a study published in The Lancet.

Researchers completed a randomized, double-blind, placebo, phase 2 study. Participants in the semaglutide arm received escalating dosages, increasing every 4 weeks until a 4 mg dose was reached. The liraglutide arm (n=103) received escalating dosages, increasing every week until a 3 mg dose was reached. The placebo arm (n=136) received matching volume injections. All treatment doses were administered by a once-daily subcutaneous injection. Researchers performed evaluations at screening, baseline, every 2 weeks though week 20, every 4 weeks for the remaining 32 weeks, and then at a follow-up at 7 weeks post-intervention. They also monitored vital sign measurements, laboratory screening, adverse events, and nutrition compliance throughout the study. The primary outcome was the percentage of weight loss at 52 weeks of intervention with secondary goals of changes in glucose metabolism, absolute change in weight, waist circumference, waist-to-hip ratio, cardiovascular risk factors, medication usage, and monitoring of adverse events.

At 52 weeks, mean weight reductions for the semaglutide arm ranged from 6.0% (0.05 mg) to 13.8% (0.4 mg) of baseline weight, patients receiving a fast-escalation dose (every 2 weeks) of semaglutide ranged from 11.4% (0.3 mg) to 16.3% (0.4 mg), the liraglutide arm had a 7.8% reduction in baseline weight, and the placebo arm had a 2.3% reduction. Eighty-three percent of participants in the semaglutide arm, 66% in the liraglutide arm, and 23% in the placebo arm lost at least 5% of baseline body weight at 52 weeks of intervention. Thirty-five percent of participants in the semaglutide arm, 6% in the liraglutide arm, and 2% in the placebo arm lost 20% or more over the 52 weeks.

Participants who increased their dose of semaglutide every 4 weeks (doses more than 0.1 mg) had significantly greater weight loss than patients who took liraglutide 3.0 mg at 52 weeks. In addition, in patients who were on the highest doses of semaglutide, weight loss continued throughout the entire study period.

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There were no clear differences in medication changes or nutritional compliance between any of the arms. Nausea was the most common adverse event, and most reported adverse events were mild or moderate.

Future studies need to analyze body composition changes and exercise adherence in regard to energy expenditure and control potential adverse event biases. 

In conclusion, semaglutide is a potential viable low-risk option to aid in weight loss through appetite suppression and enhanced satiety.

This study was supported by the Novo Nordisk. Please refer to reference for a complete list of authors’ disclosures.


O’Neil PM, Birkenfeld AL, McGowan B, et al. Efficacy and safety of semaglutide compared with liraglutide and placebo for weight loss in patients with obesity: a randomised, double-blind, placebo and active controlled, dose-ranging, phase 2 trialLancet. 2018; 392(10148):637-649.