1. What is it?
GIP stands for glucose-dependent insulinotropic polypeptide. It is a hormone that supports insulin secretion in a glucose-dependent way. It is produced in the gut and belongs to the incretins, hormones that help the body respond to a meal. Its role is not simply to lower blood sugar. Under certain conditions, it also helps regulate glucagon, a hormone that affects glucose handling differently from insulin. [185] [182]
2. Why do people turn to it?
Current interest in GIP mainly comes from developing diabetes and obesity treatments. Tirzepatide acts on GIP and GLP-1 receptors but is a separately developed substance. Studies of the hormone help explain events after meals and at different blood glucose levels. They do not automatically establish an indication for GIP in weight loss. Benefits of a medicine acting on several systems should be attributed to the whole medicine until suitable studies separate the contributions of its actions. [150] [183]
3. How does it work?
A study in 10 healthy men assessed GIP at different glucose levels. With high blood sugar, it increased insulin release. When glucose was low or normal, its effect on glucagon became more important. This shows that hormones act according to the body's circumstances. Saying GIP lowers blood sugar is therefore too simple. A fuller explanation requires information about glucose levels, meals and whether diabetes is present. [182]
4. What do studies actually show?
In a 2009 paper, natural GIP was given to 22 people with type 2 diabetes during a short meal experiment. The expected improvement in blood sugar control was not achieved, and blood sugar was higher later after the meal. This is not evidence against every new medicine stimulating the GIP receptor. The study tested a particular hormone under specific conditions for a short time. The long-term effects of a modified molecule need separate investigation. [183]
5. What do we still not know?
Older physiological experiments usually involved few participants and only a few hours of observation. They are useful for studying hormone release, but they do not settle questions about weight control over many years or the risk of diabetes complications. Results in healthy men may also differ from those in people with diabetes. Conversely, improvement with a medicine acting on both GIP and GLP-1 cannot, without further data, be attributed entirely to one receptor. A mechanism guides research; it does not predict the result. [182] [183] [150]
6. What are the risks?
The body's own GIP helps with normal regulation, but this does not mean that giving extra GIP is suitable for everyone. An experiment in type 2 diabetes showed that the intended effect may not occur. In type 1 diabetes, protection against low blood sugar was not confirmed under the conditions studied. This hormone must not be treated as a safeguard against insulin-induced low blood sugar or a basis for changing treatment independently. [183] [184]
7. Is it an approved medicine?
Natural GIP is not the same as an approved medicine acting through its receptor. One such medicine in the European Union is Mounjaro, containing tirzepatide, which also acts on GLP-1. Its approval does not cover every preparation containing GIP. Information about use and safety must concern the particular medicinal substance. A hormone abbreviation alone is insufficient to identify what was studied and what was actually approved for treatment. [150]
8. What is new in research?
A study of 12 men with type 1 diabetes appeared in the March 2026 journal issue, having been available online since December 2025. It assessed natural GIP during a meal, insulin action and exercise. It did not demonstrate protection against low blood glucose in that experiment. This adds physiological knowledge and possible research directions, but a small, short trial establishes neither treatment nor findings for all patients with diabetes. [184]
Where does this information come from?
References link to the publications and documents used. Each source includes its material type and what was reviewed; findings concern the substance, form and study population described.
Show sources and how they were checked
- Glucose-dependent insulinotropic polypeptide: a bifunctional glucose-dependent regulator of glucagon and insulin secretion in humans
Experiment in 10 healthy men; published online 7 October 2011; PubMed abstract reviewed · DOI: 10.2337/db11-0979. Accessed: 3 November 2026.
- Exogenous glucose-dependent insulinotropic polypeptide worsens post prandial hyperglycemia in type 2 diabetes
Experiment in 22 people with type 2 diabetes; published online 10 March 2009; PubMed abstract reviewed · DOI: 10.2337/db08-0958. Accessed: 3 November 2026.
- Mounjaro
EMA; current product page accessed 3 November 2026; full overview of indications and mechanism. Accessed: 3 November 2026.
- Additive insulinotropic effects of exogenous synthetic human gastric inhibitory polypeptide and glucagon-like peptide-1-(7-36) amide infused at near-physiological insulinotropic hormone and glucose concentrations
Physiological experiment in healthy volunteers; PubMed abstract read; source concerning natural hormones. Accessed: 03.11.2026.
- Glucose-dependent insulinotropic polypeptide reduces postprandial glucose excursions but does not protect from hypoglycaemia in persons with type 1 diabetes-A randomised placebo-controlled study
Small clinical study in 12 men with type 1 diabetes; online 28 December 2025, March 2026 issue; PubMed abstract reviewed · DOI: 10.1111/dom.70373. Accessed: 3 November 2026.