Dose Equivalency Between Mounjaro 7.5 mg and Ozempic
There is no direct dose equivalency between Mounjaro (tirzepatide) 7.5 mg and Ozempic (semaglutide) because they are mechanistically distinct medications with different receptor targets, and no FDA-approved conversion table exists. However, based on clinical trial data comparing weight loss and glycemic efficacy, tirzepatide 7.5 mg (a non-standard dose between the 5 mg and 10 mg FDA-approved doses) would likely produce effects somewhere between semaglutide 1.0 mg (Ozempic maximum diabetes dose) and semaglutide 2.4 mg (Wegovy obesity dose).
Why Direct Conversion Is Not Possible
Tirzepatide is a dual GIP/GLP-1 receptor agonist, whereas semaglutide is a selective GLP-1 receptor agonist—this fundamental mechanistic difference means they cannot be directly equated on a milligram-per-milligram basis. 1 Tirzepatide's affinity for the GLP-1 receptor is approximately five times lower than endogenous GLP-1, yet it achieves superior metabolic effects through its additional GIP receptor activation. 1
The dual-receptor mechanism of tirzepatide produces enhanced appetite suppression, delayed gastric emptying, improved insulin secretion, and increased energy expenditure compared to semaglutide's single-receptor action. 1 This synergistic effect explains why tirzepatide achieves greater weight loss and HbA1c reduction at seemingly "lower" GLP-1 receptor engagement.
Clinical Trial Comparisons (Actual Approved Doses)
Glycemic Control
In the SURPASS-2 head-to-head trial comparing tirzepatide with semaglutide 1.0 mg in type 2 diabetes patients:
- Tirzepatide 5 mg reduced HbA1c by 2.01% versus semaglutide 1.0 mg at 1.86% (difference -0.15%, P=0.02) 2
- Tirzepatide 10 mg reduced HbA1c by 2.24% (difference -0.39% vs semaglutide, P<0.001) 2
- Tirzepatide 15 mg reduced HbA1c by 2.30% (difference -0.45% vs semaglutide, P<0.001) 2
Weight Loss Efficacy
Tirzepatide 10 mg produces 4.67% greater weight loss than semaglutide 2.4 mg (mean difference -4.67%, 95% CI -5.91% to -3.43%, P<0.001), while tirzepatide 15 mg produces 5.92% greater weight loss (mean difference -5.92%, 95% CI -7.16% to -4.68%, P<0.001). 3
In absolute terms:
- Tirzepatide 5 mg: 15.0% weight loss at 72 weeks 4
- Tirzepatide 10 mg: approximately 19-20% weight loss 3
- Tirzepatide 15 mg: 20.9% weight loss at 72 weeks 1, 4
- Semaglutide 2.4 mg: 14.9% weight loss at 68 weeks 1
- Semaglutide 1.0 mg: approximately 7.0% weight loss in diabetes patients 1
Practical Clinical Interpretation for Tirzepatide 7.5 mg
Since 7.5 mg falls exactly midway between the FDA-approved 5 mg and 10 mg doses:
For glycemic control: Tirzepatide 7.5 mg would likely produce HbA1c reductions of approximately 2.10-2.15%, which exceeds semaglutide 1.0 mg (1.86%) but is less than tirzepatide 10 mg (2.24%). 2 This suggests tirzepatide 7.5 mg is roughly equivalent to or slightly superior to Ozempic 1.0 mg for glucose lowering.
For weight loss: Tirzepatide 7.5 mg would likely produce approximately 17-18% weight loss (interpolating between 15.0% at 5 mg and 19-20% at 10 mg), which substantially exceeds semaglutide 2.4 mg (14.9%). 4, 3 This suggests tirzepatide 7.5 mg produces weight loss exceeding the maximum obesity dose of semaglutide (Wegovy 2.4 mg).
Safety Profile Comparison
Both medications share similar gastrointestinal adverse-event profiles, with nausea occurring in 17-22% of tirzepatide patients versus 18% with semaglutide, diarrhea in 13-16% versus 12%, and vomiting in 6-10% versus 8%. 2 The dose-dependent nature of these effects means tirzepatide 7.5 mg would likely produce gastrointestinal symptoms intermediate between the 5 mg and 10 mg doses. 5
Both medications carry identical absolute contraindications: personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2 (MEN 2). 1, 4 Both require monitoring for pancreatitis and gallbladder disease. 1, 5
Cardiovascular Considerations
Semaglutide 2.4 mg has proven cardiovascular benefit with a 20% reduction in cardiovascular death, nonfatal MI, or nonfatal stroke (HR 0.80) in patients with established cardiovascular disease. 1 Semaglutide 1.0 mg demonstrated a 26% MACE reduction (HR 0.74,95% CI 0.58-0.95) in diabetic patients with cardiovascular disease. 1
Tirzepatide has demonstrated cardiovascular safety (non-inferiority) but has not achieved superiority for MACE reduction, and it did not reduce all-cause mortality compared with usual care. 6 For patients with established cardiovascular disease, semaglutide remains the preferred choice regardless of dose equivalency considerations. 1
Clinical Decision Algorithm
If the patient has established cardiovascular disease: Choose semaglutide 2.4 mg (Wegovy) over any dose of tirzepatide due to proven 20% MACE reduction. 1
If maximum weight loss is the primary goal (BMI ≥35 with severe complications): Tirzepatide 7.5 mg would produce greater weight loss than any approved semaglutide dose, though the standard FDA-approved titration to 10 mg or 15 mg would be preferable. 1, 4
If glycemic control is the primary goal in type 2 diabetes: Tirzepatide 7.5 mg would likely match or exceed Ozempic 1.0 mg, with the option to titrate to 10 mg or 15 mg for superior HbA1c reduction. 2, 6
Common Pitfalls
Do not assume tirzepatide 7.5 mg is "half the strength" of tirzepatide 15 mg—the dose-response relationship is not linear, and 7.5 mg produces substantial metabolic effects. 4
Do not prescribe tirzepatide as first-line therapy for patients with established cardiovascular disease—semaglutide's proven MACE reduction is decisive. 1
Do not use 7.5 mg as a maintenance dose—FDA-approved maintenance doses are 5 mg, 10 mg, or 15 mg weekly, and the standard titration protocol should be followed. 4, 5
Do not combine tirzepatide with other GLP-1 receptor agonists or DPP-4 inhibitors—concurrent use provides no additional benefit and increases adverse-event burden. 1