Tirzepatide
Tirzepatide is an FDA-approved dual GIP/GLP-1 receptor agonist marketed as Mounjaro for type 2 diabetes and Zepbound for chronic weight management, both delivered by subcutaneous injection.
This page is a research-orientation summary, not a dosing guide. For anything beyond general background, read the primary literature or talk to a qualified clinician — specifics like amount, frequency, or administration aren't something we publish here.
What it does & how it works
Tirzepatide is a single synthetic peptide engineered to activate both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the GLP-1 receptor, making it a dual incretin receptor agonist. Combined GIP and GLP-1 receptor activation enhances glucose-dependent insulin secretion, suppresses glucagon, and acts on hypothalamic and hindbrain circuits to reduce appetite and food intake. Fatty-acid conjugation confers albumin binding that extends its plasma half-life, and GIP receptor co-agonism is thought to add incremental metabolic and weight-loss effects beyond GLP-1 agonism alone.
Typical results seen in research
In the SURMOUNT-1 trial, adults with obesity or overweight without diabetes lost up to approximately 20.9% of body weight at the highest dose over 72 weeks, compared with about 3.1% with placebo. In SURPASS trials for type 2 diabetes, tirzepatide produced substantial HbA1c reductions along with weight loss, generally exceeding effects seen with GLP-1-only agonists in head-to-head comparisons.
How it’s commonly used
Tirzepatide is self-administered via subcutaneous injection into the abdomen, thigh, or upper arm using a prefilled single-dose pen, under a prescriber-directed dose-titration schedule intended to improve gastrointestinal tolerability. It is used together with a reduced-calorie diet and increased physical activity.
- New England Journal of Medicine · 2022 Tirzepatide Once Weekly for the Treatment of Obesity
- Diabetes, Obesity and Metabolism · 2025 Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight
- Diabetes Care · 2025 Association of Tirzepatide With Kidney Parameters in Participants With Obesity and Prediabetes From SURMOUNT-1 Over 176 Weeks
Curated from published literature for research orientation. Not an exhaustive review, and not a substitute for reading primary sources.