Dose Equivalency Between Mounjaro 7.5 mg and Ozempic
There is no established dose equivalency between Mounjaro (tirzepatide) 7.5 mg and Ozempic (semaglutide) because they are fundamentally different medications with distinct mechanisms of action, and direct dose conversion is not clinically validated or recommended by any guideline.
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 mechanistic difference means they cannot be compared on a milligram-to-milligram basis. 1 Tirzepatide's dual-receptor activation provides enhanced metabolic benefits including delayed gastric emptying, suppressed appetite, and improved insulin secretion compared to semaglutide's single-receptor action. 1
The affinity profiles differ substantially: tirzepatide binds to both GIP and GLP-1 receptors, though its affinity for the GLP-1 receptor is approximately five times less than that of endogenous GLP-1, while semaglutide is a selective GLP-1 receptor agonist with greater albumin affinity resulting in prolonged action. 1
Comparative Efficacy Data (Not Dose Equivalency)
Glycemic Control
When comparing approved doses in clinical trials, tirzepatide demonstrates superior HbA1c reduction across its dose range compared to semaglutide 1.0 mg (the maximum approved Ozempic dose for diabetes). 2 In the SURPASS-2 trial, tirzepatide at 5 mg, 10 mg, and 15 mg produced HbA1c reductions of -2.01%, -2.24%, and -2.30% respectively, compared to -1.86% with semaglutide 1.0 mg. 2
Weight Loss
Tirzepatide produces substantially greater weight loss than semaglutide across all dose levels. 1, 2 In head-to-head comparison, tirzepatide 15 mg weekly achieved 20.9% weight loss versus 14.9% with semaglutide 2.4 mg weekly—a 6% absolute difference. 1 Even tirzepatide 10 mg demonstrated a mean difference of -4.67% greater weight loss compared to semaglutide 2.4 mg. 3
Clinical Decision Algorithm for Switching
If Switching FROM Semaglutide TO Tirzepatide
Start tirzepatide at 2.5 mg weekly for 4 weeks regardless of prior semaglutide dose, then escalate to 5 mg weekly. 4 This initial low dose minimizes gastrointestinal adverse events (nausea occurs in 17-31% of patients during dose escalation). 4 After 4 weeks at 5 mg, increase to 7.5 mg or 10 mg based on efficacy and tolerability. 5
Recent evidence suggests that early escalation to 10 mg may be beneficial for patients switching from semaglutide 1.0 mg who had inadequate glycemic response, as the 10 mg group experienced significant HbA1c reduction (-0.7%) whereas the 7.5 mg group showed no significant changes. 5
If Switching FROM Tirzepatide TO Semaglutide
Discontinue tirzepatide and initiate semaglutide at 0.25 mg weekly the following week, then follow the standard titration schedule to reach 2.4 mg weekly over 16 weeks. 1 The standard semaglutide titration must be followed regardless of prior tirzepatide dose to minimize gastrointestinal adverse effects: Week 1-4: 0.25 mg, Week 5-8: 0.5 mg, Week 9-12: 1.0 mg, Week 13-16: 1.7 mg, Week 17+: 2.4 mg. 1
Practical Considerations
When to Choose Tirzepatide Over Semaglutide
Prioritize tirzepatide when maximum weight loss is the primary goal, as it achieves approximately 6% greater weight reduction than semaglutide 2.4 mg. 1 Tirzepatide also demonstrates superior cardiometabolic benefits including greater waist circumference reduction, superior triglyceride reduction, and better fasting glucose control. 1
When to Choose Semaglutide Over Tirzepatide
For patients with established cardiovascular disease, semaglutide 2.4 mg weekly is preferred due to proven cardiovascular benefit, with a 20% reduction in cardiovascular death, nonfatal MI, or nonfatal stroke (HR 0.80). 1 Semaglutide has demonstrated a 26% reduction in major adverse cardiovascular events in patients with type 2 diabetes (HR 0.74,95% CI 0.58-0.95). 1
Cost Comparison
Tirzepatide costs approximately $1,272 per 30-day supply (median AWP) compared to $1,619 for semaglutide 2.4 mg, making tirzepatide slightly less expensive while providing superior weight loss efficacy. 6, 7 The cost needed to treat per 1% body weight reduction is $985 for tirzepatide versus $1,845 for semaglutide. 7
Safety Profile
Both medications share similar adverse-event profiles, with gastrointestinal effects predominating (nausea 17-22% for tirzepatide vs 18% for semaglutide; diarrhea 13-16% vs 12%; vomiting 6-10% vs 8%). 2 Both carry identical contraindications: personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 (MEN 2). 1
Critical Pitfall to Avoid
Do not attempt to "convert" doses between these medications—they are not interchangeable. 1 Always restart titration at the recommended starting dose when switching between agents to ensure safety and tolerability. The question of "equivalency" is clinically inappropriate because these are distinct drug classes with different mechanisms, and treatment decisions should be based on patient-specific factors (cardiovascular disease status, weight loss goals, tolerability) rather than attempting dose matching. 1