GIP
Glucose-dependent insulinotropic polypeptide · Gastric inhibitory polypeptide · GIP(1-42)
An endogenous incretin hormone from K-cells of the duodenum that stimulates insulin release, promotes fat storage, and is one of the two targets of tirzepatide — the first dual GIP/GLP-1 receptor agonist.
Half-Life
~7 minutes (native GIP, rapidly inactivated by DPP-IV at Tyr-Ala N-terminus)
MW
4983.5 Da
Amino Acids
42 AA
Evidence
High Evidence
Regulatory Status
Endogenous hormone extensively studied. Tirzepatide (dual GIP/GLP-1 agonist) is FDA-approved (Mounjaro for T2D, Zepbound for obesity). Selective GIPR agonists are in clinical development. GIP itself is not therapeutically available.
In Plain English
One of the gut's two main "food is here, release insulin" signals. When you eat fat or carbs, your small intestine releases GIP to help your pancreas produce insulin at the right time. It's also the second target of Mounjaro/Zepbound (tirzepatide) — adding GIP action on top of GLP-1 action is why tirzepatide beats semaglutide for weight loss.
Overview
GIP is a 42-amino acid peptide produced by K-cells in the proximal small intestine (duodenum and jejunum) in response to fat and carbohydrate ingestion. It is a key incretin — a gut hormone that amplifies glucose-stimulated insulin secretion. GIP stimulates beta-cell insulin release, promotes fat deposition in adipocytes, and has bone anabolic effects. The GIP receptor (GIPR) is expressed on pancreatic beta-cells, adipocytes, bone, and the brain. Unlike GLP-1, GIP does not inhibit gastric emptying, making it better tolerated from a GI standpoint. Critically, GIP is the second target of tirzepatide (Mounjaro/Zepbound), and GIPR agonism appears to amplify GLP-1 receptor agonist effects on weight loss — the underlying mechanism is still debated but involves adipose tissue remodeling and central satiety signaling.
Common Formats
- Research-grade synthetic peptide (IV/SC research)
- Not commercially available as standalone therapeutic
Storage Notes
Lyophilized research peptide: -20°C long-term. Reconstituted: 4°C, stable 1-2 weeks. DPP-IV rapidly inactivates GIP in plasma — consider DPP-IV inhibitors or degradation-resistant analogs for in vivo research.
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Related Compounds
Tirzepatide
A dual GIP/GLP-1 receptor agonist with FDA approval showing up to 22% weight loss — superior to semaglutide in head-to-head trials.
Semaglutide
A GLP-1 receptor agonist with FDA approval for type 2 diabetes and obesity, demonstrating unprecedented weight loss results in clinical trials.
Retatrutide
A triple GIP/GLP-1/glucagon receptor agonist in Phase III trials, showing over 24% weight loss — potentially the most powerful metabolic peptide in development.
Liraglutide
A once-daily GLP-1 receptor agonist with FDA approval for T2D and obesity, the predecessor to semaglutide with strong clinical evidence.
Educational Disclaimer: All information on this page is for educational and research purposes only. This does not constitute medical advice, diagnosis, or treatment recommendation. Consult a qualified healthcare professional.