Semaglutide vs. Tirzepatide: How the Top Two GLP-1s Compare

Almost every modern GLP-1 conversation comes down to two molecules: semaglutide (sold as Ozempic® and Wegovy®) and tirzepatide (sold as Mounjaro® and Zepbound®). Both reduce appetite and improve blood sugar, both are weekly injections, and both have transformed medical weight loss — but they aren't identical.

Semaglutide mimics one gut-hormone receptor: GLP-1. Tirzepatide mimics two — GLP-1 and GIP — which is why it's described as a dual agonist. In practice, both quiet appetite and slow stomach emptying, but the extra mechanism in tirzepatide is thought to contribute to its slightly larger average weight-loss numbers in studies.

In large clinical trials paired with diet and lifestyle changes, semaglutide produced average weight loss of around 15% of body weight, and tirzepatide around 20%. These are averages — individual results vary widely, and the best medication for any one person isn't always the one with the biggest headline number.

Both share the same main side effects — nausea and other digestive symptoms, usually mild and most noticeable while the dose is increasing. The right choice depends on your medical history, how you tolerate the medication, insurance, cost, and availability. A licensed provider weighs all of that; this comparison is a starting point, not a prescription.