From the Guidelines
Mounjaro (tirzepatide) is more effective than Ozempic (semaglutide) for weight reduction, with clinical trials showing that tirzepatide produces greater weight loss (approximately 15-20% of body weight) compared to semaglutide (approximately 10-15% of body weight) 1.
Mechanism of Action
Mounjaro is a dual GIP/GLP-1 receptor agonist that activates both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors, while Ozempic is a GLP-1 receptor agonist only. This dual-action mechanism gives Mounjaro an advantage in weight reduction.
Weight Loss Effectiveness
Clinical trials have shown that tirzepatide produces greater weight loss compared to semaglutide. The SURMOUNT-1 trial showed a dose-dependent weight-loss benefit with tirzepatide, with a mean weight change of up to −20.9% compared to placebo in obese adults without diabetes over 72 weeks 1. In contrast, the STEP trials showed a mean weight loss of 14.9% and 16.0% with semaglutide compared to placebo in individuals with obesity without diabetes 1.
Administration and Side Effects
Both medications are administered as weekly subcutaneous injections, with Mounjaro typically starting at 2.5mg and potentially increasing to 15mg, while Ozempic usually starts at 0.25mg and may increase to 2mg. Side effects for both include nausea, vomiting, and diarrhea, which often improve over time.
Key Differences
The key differences between Mounjaro and Ozempic are:
- Mechanism of action: Mounjaro is a dual GIP/GLP-1 receptor agonist, while Ozempic is a GLP-1 receptor agonist only
- Weight loss effectiveness: Mounjaro produces greater weight loss compared to Ozempic
- Administration: Both medications are administered as weekly subcutaneous injections, but with different dosing regimens
Overall, Mounjaro (tirzepatide) is a more effective option for weight reduction compared to Ozempic (semaglutide) due to its dual-action mechanism and greater weight loss effectiveness 1.
From the FDA Drug Label
The effectiveness of MOUNJARO was not impacted by age, gender, race, ethnicity, region, or by baseline BMI, HbA1c, diabetes duration, or renal function. Treatment with MOUNJARO 10 mg and 15 mg once weekly for 40 weeks resulted in a statistically significant reduction in HbA1c compared with semaglutide 1 mg once weekly. Body Weight (kg) Baseline (mean) 93.7 92.5 94.8 93.8 Change at Week 40b-5.7 -7.6 -9.3 -11.2 Difference from semaglutideb (95% CI) -- -1.9c (-2.8, -1.0) -3.6d (-4.5, -2.7) -5.5d (-6.4, -4. 6)
Mode of Action and Effectiveness for Weight Reduction:
- Mounjaro (tirzepatide) and Ozempic (semaglutide) are both used for the treatment of type 2 diabetes mellitus.
- The mode of action of both drugs involves glucose-dependent insulin secretion, but Mounjaro has an additional mechanism of action as a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist.
- In terms of effectiveness for weight reduction, Mounjaro has been shown to result in a statistically significant reduction in body weight compared to semaglutide.
- The difference in weight reduction between Mounjaro and semaglutide was -1.9 kg, -3.6 kg, and -5.5 kg for Mounjaro 5 mg, 10 mg, and 15 mg, respectively, compared to semaglutide 1 mg. 2
From the Research
Mode of Action
- Mounjaro (tirzepatide) is a dual glucose-dependent insulinotropic polypeptide (GIP) receptor and GLP-1 receptor agonist, which means it works by activating both GIP and GLP-1 receptors in the body 3, 4.
- Ozempic (semaglutide) is a selective GLP-1 receptor agonist, which means it only activates the GLP-1 receptor in the body 5.
- The dual action of Mounjaro may provide additional benefits in terms of glucose control and weight reduction compared to Ozempic, which only has a single mechanism of action 5.
Effectiveness in Weight Reduction
- Studies have shown that Mounjaro is effective in reducing body weight, with a significant proportion of patients achieving a weight loss of more than 10% of their baseline body weight 5.
- Mounjaro has been shown to be more effective in reducing body weight compared to Ozempic, with a greater percentage of patients achieving a weight loss of more than 10% of their baseline body weight 5.
- The weight loss effects of Mounjaro are thought to be due to its ability to reduce appetite and improve insulin sensitivity, as well as its effects on glucose metabolism 4, 5.
- Both Mounjaro and Ozempic have been shown to be effective in reducing HbA1c levels and improving glycemic control, but Mounjaro may have an advantage in terms of its ability to reduce body weight and improve insulin sensitivity 5.