The glucagon like peptide-1 ( GLP-1) receptor , activated complex with an agonist (semaglutide) and G-proteins
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While semaglutide has been in the biopharma limelight for its impressive effects on weight loss in adults with and without type 2 diabetes, it looks like it could soon be playing second fiddle to another glucagon-like peptide 1 GLP-1 receptor agonist-based medication when it comes to weight loss.

A study published in JAMA Internal Medicine contrasting the effects of taking semaglutide and tirzepatide—consisting of both a GLP-1 receptor agonist and a gastric inhibitory polypeptide—on patients with type 2 diabetes showed that tirzepatide has a greater impact on weight loss than semaglutide. 

Electronic health record (EHR) data from 35 states was analyzed by Truveta Research and showed that people with type 2 diabetes who took tirzepatide were 1.8 times more likely to lose five percent of their body weight compared to people who took semaglutide. They were also 2.5 times more likely to lose 10 percent of their body weight compared to people who took semaglutide, and 3.2 times more likely to lose 15 percent of their body weight compared to people who took semaglutide.

It turns out that the idea of tirzepatide producing more significant weight loss than semaglutide in patients with type 2 diabetes isn’t new, as demonstrated in a New England Journal of Medicine article reporting clinical data for tirzepatide versus semaglutide once weekly in patients with type 2 diabetes. Along these lines, data from head-to-head trials comparing these therapies in patients with overweight or obesity had not yet been made available before the publication of the research by Truveta Research and the Providence Health System.

It’s a major win for the developers of tirzepatide (Mounjaro), Eli Lilly and Company, over those of semaglutide (Ozempic), Novo Nordisk.

Designed for diabetes, not weight loss

The goal of the study was to find out how much weight loss and gastrointestinal side effects happened in adults who were overweight or had obesity and were taking tirzepatide or semaglutide, both of which are approved for type 2 diabetes, in a clinical setting. Because this study was done with patients with type 2 diabetes, it’s worth pointing out that it looked at Ozempic and Mounjaro rather than Wegovy and Zepbound, respectively, as NBC News and Forbes have incorrectly reported. 

While both Ozempic and Wegovy contain the active ingredient semaglutide, Wegovy contains higher doses of the GLP-1 RA (2.4 mg) and is designed for weight loss in adults with obesity or some adults with overweight and weight-related medical problems, such as heart disease. Ozempic has lower doses of semaglutide—either 0.5 mg, 1 mg, or 2 mg—and was developed specifically to lower blood sugar levels in type 2 diabetes patients and not weight loss.

Similarly, Zepbound and Mounjaro share the same active ingredient, tirzepatide. Still, they are FDA-approved to treat different health conditions: Zepbound is indicated for weight loss, while Mounjaro is indicated for type 2 diabetes. Other similarities include their dosage schedules and method of administration (subcutaneous injection). There are a few other nuances between Zepbound and Mounjaro, including their side effects, cost, and insurance coverage.

So, future studies are needed to compare Wegovy and Ozempic in patients without type 2 diabetes.

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