Wegovy vs Mounjaro: how the two compare for weight loss

The quick comparison

Both are once-weekly injections that quiet appetite and improve blood sugar, and both are titrated up slowly. The core differences: Wegovy is semaglutide and works on one incretin receptor (GLP-1), while Mounjaro is tirzepatide and works on two (GLP-1 and GIP). That dual action is part of why tirzepatide tends to produce more average weight loss. There is also an approval wrinkle worth understanding before you compare them head to head.

The approval wrinkle

Wegovy is approved specifically for weight management. Mounjaro is approved for type 2 diabetes, not weight loss; its identical-drug twin approved for weight management is Zepbound. So a strictly like-for-like weight-loss comparison is really Wegovy versus Zepbound, but because so many people ask about Mounjaro by name, the practical comparison is the same molecule. Our semaglutide vs tirzepatide post covers the drugs at the molecule level.

Weight loss

Across their trials, tirzepatide (Mounjaro, Zepbound) generally produced greater average weight loss than semaglutide (Wegovy, Ozempic), and a head-to-head diabetes trial (SURPASS-2) found tirzepatide led to more weight loss and blood-sugar improvement than semaglutide at the doses studied. That does not mean it is better for everyone: individual results vary widely, and the best drug is the one you tolerate and stay on. Wegovy also has a large cardiovascular outcome trial (SELECT) behind it, which is a meaningful point in its favor.

Side effects

The side-effect profiles are broadly similar because both are incretin drugs: nausea, diarrhea or constipation, and other gut effects are most common and cluster during dose increases, and both carry the class thyroid C-cell warning and cautions around pancreatitis and gallbladder issues. Neither is clearly gentler for everyone; tolerance is individual, and starting low and titrating slowly matters more than the choice of molecule.

Which is right for you?

It depends on your goal (weight, diabetes, or both), how you tolerate each, cost and insurance coverage, and your clinician's read of your history. If maximum average weight loss is the priority and you tolerate it, tirzepatide has the edge in the data; if cardiovascular outcome evidence or a specific coverage situation matters, semaglutide may fit better. Our liraglutide vs semaglutide post and Saxenda vs Wegovy post cover other options. Tracking dose, weight, and side effects in DoseLog gives your prescriber the real-world picture if you switch between them.