Dual and triple incretin agonists (GIP/GLP-1 and GIP/GLP-1/glucagon)
Dual and triple incretin agonists are single molecules that switch on the GIP receptor and the GLP-1 receptor, and in the triple agonists the glucagon receptor too. Tirzepatide is approved for type 2 diabetes, weight management, and obstructive sleep apnea with obesity, and the triple agonist retatrutide is still in trials. Stomach upset, nausea, vomiting, diarrhea, and constipation are the most common side effects, and heart rate tends to rise a little. Like other incretin drugs they carry a boxed warning about thyroid C-cell tumors in rodents and are avoided in people with a personal or family history of medullary thyroid cancer.