Different Medications, Different Mechanisms
Ozempic contains semaglutide, a GLP-1 receptor agonist. Mounjaro contains tirzepatide, a dual-agonist that targets both GLP-1 and GIP receptors. This fundamental difference in mechanism is why they produce different results. Both are FDA-approved for type 2 diabetes and widely used off-label (or through weight-specific versions) for weight loss.
Weight Loss Results Compared
In clinical trials, Mounjaro (tirzepatide) showed greater weight loss than Ozempic (semaglutide). The SURMOUNT trials showed tirzepatide patients losing up to 22.5% of body weight, while the STEP trials showed semaglutide patients losing about 15%. For a deeper dive, see our tirzepatide vs semaglutide comparison.
Side Effects
Both medications share similar gastrointestinal side effects — nausea, vomiting, diarrhea, and constipation are most common during dose escalation. Mounjaro may have slightly higher rates of certain GI symptoms at its highest doses, but overall tolerability is comparable. Most side effects improve over time. Read our side effects guide for management strategies.
Cost Comparison
Both are expensive at retail — Ozempic around $900–$1,000/month, Mounjaro around $1,000–$1,100/month. Compounded versions through telehealth providers are significantly cheaper: compounded semaglutide from $199/month, compounded tirzepatide from $300–$500/month. See our cost guide for a full breakdown.
Which One Should You Choose?
If maximum weight loss is your priority, tirzepatide (Mounjaro/Zepbound) has a clinical edge. If you want a longer track record and wider availability, semaglutide (Ozempic/Wegovy) is the more established option. Many patients start with semaglutide and switch to tirzepatide if they hit a plateau. Take our quiz to find a provider that offers the medication best suited to your needs.