Reduces amount of glucose released by the liver
Decreases insulin resistance
Makes the beta cells stronger in the pancreas
As a member of the GLP-1RA class of drugs, Mounjaro works in a similar way as others in this class. A good description of how these work is here:
“The incretin system has become an important target in the treatment of type 2 diabetes in recent years (1). Incretins are hormones produced by the intestinal mucosa in response to oral intake of nutrients that enhance glucose-stimulated insulin secretion and lower blood glucose levels. Incretins also reduce insulin release when glucose levels are near normal. It has been shown that secretion of insulin is greater in response to oral glucose ingestion than to an isoglycemic intravenous glucose infusion, a phenomenon referred to as “the incretin effect” (2,3). Two incretin hormones have been identified: glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1 (GLP-1) (4). GLP-1 is of particular interest for its glucose-lowering effects (5), as well as its ability to slow gastric emptying and suppress secretion of glucagon (1).
The incretin effect is reduced in people with type 2 diabetes (6). The most recent understanding of this deficit suggests that it relates to deterioration of the GLP-1 effect, with impaired capacity to secrete insulin, increasing insulin resistance, and hyperglycemia, perhaps leading to a decrease in GLP-1 receptor expression and resulting in GLP-1 resistance (7). Administration of GLP-1 receptor agonists stimulates GLP-1 receptors, thereby increasing insulin secretion in response to oral and intravenous glucose to similar extents; this means the magnitude of the incretin effect should remain unchanged (8).”
From:
Glucagon-Like Peptide 1 Receptor Agonists for Type 2 Diabetes
Diabetes Spectrum, August 2017