Zepbound
Zepbound is the brand name for tirzepatide indicated for chronic weight management. It is the same molecule as Mounjaro, but at the same dose strengths labeled for weight loss rather than diabetes. Tirzepatide is unusual in the GLP-1 family because it activates two incretin hormone receptors — GIP (glucose-dependent insulinotropic polypeptide) and GLP-1. In head-to-head trials, tirzepatide has produced greater average weight loss than semaglutide, with average reductions around 20% of starting body weight at 72 weeks.
Educational reference only — your prescriber sets your actual schedule.
How Zepbound works
Tirzepatide activates both GIP and GLP-1 receptors. The combined activation appears to produce stronger appetite suppression and metabolic effects than activating GLP-1 alone. It slows gastric emptying, enhances insulin response to meals, and reduces hunger signals in the brain.
Dose schedule
Zepbound follows a six-step titration: 2.5, 5, 7.5, 10, 12.5, and 15 mg weekly, each step lasting at least four weeks. Many patients see meaningful weight loss starting at the 5 mg or 10 mg dose. The full 15 mg dose is the maximum, not required for everyone. Reference ladder only — your prescriber sets your actual schedule.
Common side effects
Similar profile to other GLP-1s: nausea, diarrhea, vomiting, constipation, abdominal pain, fatigue. Injection site reactions are slightly more common with Zepbound than with semaglutide-based medications. Most gastrointestinal effects improve over the first 4-8 weeks at any given dose.
Comparison with Wegovy
The SURMOUNT-5 trial (presented 2025) was the first direct head-to-head comparison: at 72 weeks, tirzepatide produced about 20% body weight reduction versus about 14% for semaglutide. Tolerability profiles were broadly similar, though tirzepatide patients reported slightly more injection-site reactions and semaglutide patients slightly more nausea. Individual response varies and one drug may suit you better than the other.
Storage and handling
Refrigerated until first use. After first use, may be stored unrefrigerated up to 86°F (30°C) for up to 21 days. Do not freeze. Pre-filled single-use pens are discarded after each dose.
Cost and insurance
Zepbound's list price is around $1,060 per month. Lilly also offers Zepbound in single-dose vials at a reduced cost through LillyDirect for self-pay patients. Insurance coverage for weight-management indications varies; the Lilly Savings Card may reduce cost for commercially insured patients.
Last reviewed: 2026-05-24
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