GIP

Also called: glucose-dependent insulinotropic polypeptide

Clinical reviewer: Jacob Moore, MD · Last checked September 16, 2026

What is GIP?

GIP is a 42-amino-acid hormone released from intestinal K cells that stimulates insulin release after eating. It accounts for 60% to 80% of the after-meal insulin response and is one of the two incretin hormones, alongside GLP-1, targeted by dual-agonist drugs like tirzepatide.

What does GIP do in the body?

Glucose-dependent insulinotropic polypeptide (GIP) is a 42-amino-acid hormone synthesized and released from intestinal K cells in response to eating glucose or fat [1]. It accounts for 60% to 80% of the after-meal insulin response, consistent with the view that it is the principal physiological incretin, and it plays a major role in how the body stores and uses nutrients [1].

How is GIP different in people with obesity or type 2 diabetes?

GIP is overexpressed in people with obesity, which researchers say may worsen the insulin resistance seen with type 2 diabetes by increasing nutrient uptake and storage in fat cells [1]. Yet combining GIP agonism with a GLP-1 analogue has shown benefit for treating obesity, through mechanisms not yet fully understood [1].

Why is GIP a drug target?

GIP is one of the two incretin hormones, and drug developers now target both its receptor and GLP-1's in a single molecule. Mounjaro (tirzepatide) is labeled as "a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist" [2], making it a dual agonist rather than a GLP-1-only medication.

Related terms

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Sources

  1. Wolfe MM, Boylan MO, Chin WW — Glucose-Dependent Insulinotropic Polypeptide in Incretin Physiology (Endocr Rev, 2025)
  2. MOUNJARO (tirzepatide) — FDA Prescribing Information

This entry is for education and is not medical advice. Talk with a licensed clinician about your own situation before starting, stopping, or changing any treatment.

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