What is the role of GIP and GLP-1 in Mounjaro’s action?
Mounjaro (tirzepatide) works by mimicking two natural gut hormones—GLP-1 and GIP—that help regulate blood sugar and appetite after eating. Activating GLP-1 receptors prompts the pancreas to release insulin when glucose is high, reduces the liver’s glucose output, and slows stomach emptying, which lowers blood sugar and reduces appetite. Activating GIP receptors further supports glucose-dependent insulin release and enhances the effects of GLP-1 on both blood sugar control and weight regulation. Together, this dual-agonist effect offers a combined benefit for managing diabetes and supporting weight loss. In UK healthcare guidance, this dual mechanism is recognised as central to tirzepatide’s role in improving glycaemic control and weight outcomes when used alongside lifestyle measures.
- GLP-1 action: increases insulin when glucose is high, reduces liver glucose output, and slows stomach emptying to lower blood sugar.
- GIP action: supports glucose-dependent insulin release and boosts GLP-1’s effects on blood sugar and weight.
- Dual-agonist effect: combining GLP-1 and GIP provides added benefits for glucose control and appetite regulation.
- Acts after meals: both are “incretins,” released after eating to help the body manage glucose effectively.
- UK context: recognised in NHS and NICE guidance as part of tirzepatide’s use for diabetes and weight management alongside diet and activity.