Why Mounjaro produces more weight loss
The key difference is Mounjaro's dual receptor action. While Ozempic only activates GLP-1 receptors to reduce appetite and slow digestion, Mounjaro also activates GIP receptors — which appear to enhance fat metabolism and energy expenditure. Think of it as pressing two buttons instead of one.
The SURMOUNT-1 trial showed Mounjaro producing approximately 6 percentage points more weight loss than what semaglutide achieves — a clinically meaningful difference.
If you have type 2 diabetes
Both medications are excellent for blood sugar control. Ozempic has the advantage of PBS subsidisation (~$41/script vs $350–500/month for Mounjaro). However, if you also need significant weight loss, Mounjaro's greater effectiveness may justify the higher out-of-pocket cost.
Discuss the trade-offs with your endocrinologist or GP.
If you want weight loss medication
Mounjaro is the clear choice. It's approved for weight loss, more effective, and actually available for this purpose. Ozempic is restricted for weight loss since October 2024.
For a fairer comparison of your actual weight loss options, see Wegovy vs Mounjaro — both are approved and available for weight management.