Tirzepatide

Tirzepatide (GIP/GLP-1 Dual Agonist)

Evidence & Status

  • FDA Approved
  • Strong Human Evidence
  • Established

At a Glance

An FDA-approved dual hormone receptor agonist activating both GIP and GLP-1 pathways, used in the treatment of type 2 diabetes and chronic weight management. Clinical trials have demonstrated among the largest weight reductions of any pharmacological compound studied to date.

Plain English

Researchers study tirzepatide because it activates two separate hormone signalling systems simultaneously — GLP-1, which helps regulate blood sugar and appetite, and GIP, which influences how the body stores fat and responds to food. Large clinical trials have shown substantial reductions in blood glucose and body weight. Scientists are continuing to explore its potential effects on heart health, liver conditions, and other metabolic disorders. Like semaglutide, it represents one of the most significant areas of active metabolic medicine research, with a strong clinical evidence base from human trials.

Overview

A dual GIP and GLP-1 receptor agonist available as Mounjaro for type 2 diabetes and Zepbound for chronic weight management and moderate-to-severe obstructive sleep apnea in adults with obesity. Product-specific labels define approved uses and dosing.

Research Summary

Large randomized trials support tirzepatide for labeled metabolic uses. SURMOUNT-1 reported substantial mean weight reduction over 72 weeks in adults with obesity or overweight, and SURPASS-2 found greater HbA1c and weight reductions than semaglutide 1 mg in type 2 diabetes. SURPASS-CVOT (completed June 2025) found that tirzepatide was noninferior to dulaglutide for the major adverse cardiovascular event composite in adults with type 2 diabetes at elevated cardiovascular risk; superiority was not established. SURMOUNT-MMO is an active cardiovascular morbidity and mortality outcomes trial that is no longer recruiting new participants; it has an estimated completion date of 2027 and has not reported primary results. The current Zepbound label includes moderate-to-severe obstructive sleep apnea in adults with obesity; each dose increase requires a minimum of four weeks on the current dose before escalation.

Research Areas

  • Type 2 diabetes
  • Obesity
  • Metabolic syndrome
  • NASH/MASH
  • Cardiovascular risk (SURPASS-CVOT)

Safety & Risks

Serious Risks

  • Medullary thyroid carcinoma (boxed warning)
  • Pancreatitis
  • Hypoglycemia (with insulin)
  • Bowel obstruction
  • Gallbladder disease

Reported Side Effects

  • Nausea
  • Diarrhea
  • Decreased appetite
  • Vomiting
  • Constipation
  • Abdominal pain
  • Injection site reactions
United States
Prescription: Mounjaro is FDA-approved for type 2 diabetes; Zepbound is FDA-approved for chronic weight management and moderate-to-severe obstructive sleep apnea in adults with obesity
United Kingdom
Prescription (MHRA-approved as Mounjaro for T2D and obesity)
Australia
Prescription (TGA-approved)
Canada
Prescription (Health Canada approved)

Citations & Sources