When it comes to weight loss, Mounjaro (Tirzepatide) seems to have a significant advantage over Ozempic (Semaglutide). This is largely because Mounjaro combines two modified incretin hormones, GLP-1 and GIP, while Ozempic only contains the modified GLP-1 hormone.
Clinical Trial Results: Mounjaro vs. Ozempic
A major clinical trial published in JAMA compared the weight loss effects of Ozempic and Mounjaro. The results showed that Mounjaro was more effective in promoting weight loss.
Study Details:
- Semaglutide Group: 32,000 participants, 0.5mg once weekly for 1 year
- Tirzepatide Group: 9,100 participants, 5.0mg once weekly for 1 year
- Mean Body Mass: 110kg
- Side Effects: Similar rates in both groups
Weight Loss Results:
- At 3 months: Mounjaro led to 2.4% greater weight loss
- At 6 months: Mounjaro showed 4.3% greater weight loss
- At 12 months: Mounjaro achieved 6.9% greater weight loss
The study found that Mounjaro resulted in more significant weight loss than Ozempic at every measured interval, especially in non-diabetic participants, who experienced a stronger weight loss effect from GLP-1 agonists.
Dosage Differences and Study Limitations
However, the trial had some limitations due to dosage differences between the two medications:
- Mounjaro: Tested at 5.0mg, which is 1/3 of its maximum approved dosage (15mg).
- Ozempic: Tested at 0.5mg, which is about 1/5 of its maximum approved dosage (2mg or 2.4mg as Wegovy).
Because of these dosage disparities, the trial may have favored Tirzepatide. For a more accurate comparison, a study with both medications tested at their maximum approved doses would be ideal.
Which is Better?
The study suggests that Mounjaro may be more effective for weight loss than Ozempic. However, due to the differences in dosages used in the trial, it’s difficult to recommend one over the other in clinical practice definitively.
