Tirzepatide: Overview, Dosage, Side Effects & Research
FDA-approved dual-action peptide delivering up to 22% weight loss — the gold standard of prescription weight management.
Also known as: Mounjaro, Zepbound, LY3298176
What is Tirzepatide?
Tirzepatide is a once-weekly injectable that simultaneously activates GIP and GLP-1 receptors. GLP-1 activation suppresses appetite, slows gastric emptying, and enhances insulin secretion. GIP activation amplifies insulin response and may improve lipid metabolism and fat storage patterns. The dual mechanism produces greater weight loss than GLP-1-only drugs like semaglutide.
Dosage Overview
| Level | Dose |
|---|---|
| Starting / Low | 2.5 mg |
| Typical / Maintenance | 10-15 mg |
| Maximum (studied) | 15 mg |
Start at 2.5mg weekly for 4 weeks, then increase by 2.5mg every 4 weeks as tolerated. Maximum approved dose is 15mg weekly.
Full dosage guide with titration schedule →Side Effects
| Side Effect | Frequency |
|---|---|
| Nausea | common |
| Diarrhea | common |
| Vomiting | common |
| Constipation | common |
| Stomach pain | common |
| Decreased appetite | common |
Clinical Research
Participants on 15mg tirzepatide lost an average of 22.5% of body weight over 72 weeks, compared to 2.4% for placebo.
Tirzepatide 15mg reduced HbA1c by 2.46% vs 2.33% for semaglutide 1mg, and produced greater weight loss (12.4kg vs 6.2kg).
Best Used For
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Frequently Asked Questions
What is the difference between Mounjaro and Zepbound?
Both contain tirzepatide (the same active ingredient) but are approved for different indications. Mounjaro is FDA-approved for type 2 diabetes management, while Zepbound is approved for chronic weight management in adults with obesity or overweight with a weight-related condition.
How much weight can I lose on Tirzepatide?
Clinical trials show an average of 22.5% body weight reduction at the highest dose (15mg) over 72 weeks. Individual results vary based on diet, activity, and adherence.
Is compounded Tirzepatide available?
Yes. During FDA-designated drug shortages, 503B compounding pharmacies can legally produce tirzepatide. Availability varies. Always verify the pharmacy's 503B status and request a Certificate of Analysis for purity verification.
How does Tirzepatide compare to Semaglutide (Ozempic/Wegovy)?
Tirzepatide (dual GIP/GLP-1) consistently outperforms semaglutide (GLP-1 only) on weight loss in head-to-head trials. The SURPASS-2 trial showed tirzepatide produced roughly twice the weight loss of semaglutide 1mg.
Where to Source Tirzepatide
Sourcing guidance, supplier vetting criteria, and price benchmarks.
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