Peptide library · Weight & metabolism
Tirzepatide
Mounjaro · Zepbound
FDA approved20.9%average weight loss over 72 weeks in SURMOUNT-1 (2,539 adults), vs 3.1% on placebo
What it is
One molecule that activates two gut hormone receptors, GIP and GLP-1. Taken once a week.
Why researchers are interested
- First drug ever approved for obstructive sleep apnea (2024): 25 to 29 fewer breathing interruptions per hour.
- Approved in Aug 2026 to reduce heart risk in type 2 diabetes after the 13,165 person SURPASS-CVOT trial.
- Head to head vs semaglutide (SURMOUNT-5): 20.2% vs 13.7% weight loss.
Good to know
- Prescription medicine (Mounjaro 2022, Zepbound 2023).
- Stomach side effects are the most common reason people stop.
Evidence level: 5 of 5
Sources
NEJM 2022 (SURMOUNT-1); NEJM 2025 (SURPASS-CVOT); Novo Nordisk REDEFINE 4
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Educational content only. Not medical advice. Last reviewed 2026-10-17.