Tirzepatide[Zepbound; Mounjaro]
Compound snapshot
Class
Dual GIP and GLP-1 receptor agonist
FDA approved
Yes — product-specific indications include chronic weight management, type 2 diabetes and moderate-to-severe obstructive sleep apnoea in adults with obesity
Clinical development
Approved
Last reviewed
September 2026
Research areas
Body weight / Type 2 diabetes / Obstructive sleep apnoea / Appetite regulation
Regulatory status
FDA-approved prescription medicine — indication depends on product
Internet attention
Very high
Registry query
tirzepatide
A long-acting dual GIP and GLP-1 receptor agonist. Zepbound is approved for chronic weight management and for moderate-to-severe obstructive sleep apnoea in adults with obesity; Mounjaro has a separate type 2 diabetes indication.
Reality check — what we actually know
Supported by human evidence
- SURMOUNT-1: mean weight change reached −20.9% at 72 weeks in the highest studied group versus −3.1% with placebo in adults without diabetes.
- SURMOUNT-5 directly compared the medicines: −20.2% mean weight change with tirzepatide versus −13.7% with semaglutide at 72 weeks.
- FDA-reviewed evidence supports product-specific indications for weight management, type 2 diabetes and obstructive sleep apnoea.
Animal research only
- Rodent pharmacology informed development, but approved uses are supported by human randomised trials.
Mechanistically plausible
- Combined GIP and GLP-1 receptor activation affects appetite, glucose-dependent insulin release and gastric emptying.
Common internet claims
- "It always produces more weight loss than semaglutide" — SURMOUNT-5 reports group averages, not guaranteed individual outcomes.
- "Weight stays off automatically after stopping" — withdrawal research shows substantial regain is common.
Not established
- That it is the best option for every individual
- Completed dedicated obesity cardiovascular-outcomes evidence — SURMOUNT-MMO remains ongoing
- Safety or equivalence of unapproved compounded or research-market products
Evidence distribution
Each band is a live PubMed search for Tirzepatide, filtered to that kind of study. Top is the strongest evidence; the base is reasoning, not proof. A band with no records means that kind of study has not been published for this compound yet.
Mechanism and reported findings
Activates both GIP and GLP-1 receptors. Together these signals improve glucose-dependent insulin release, reduce appetite and food intake, and slow stomach emptying. The dual action distinguishes it from semaglutide's GLP-1-only mechanism.
- SURMOUNT-1 (NEJM, 2022): mean body-weight change at 72 weeks was −15.0%, −19.5% and −20.9% across the three studied groups versus −3.1% with placebo in adults without diabetes
- SURMOUNT-5 (NEJM, 2025): mean weight change was −20.2% with tirzepatide versus −13.7% with semaglutide at 72 weeks in a direct open-label randomised trial
- FDA-approved for chronic weight management and for moderate-to-severe obstructive sleep apnoea in adults with obesity
- Large randomised programmes support glucose control and weight-management efficacy
Strength of the evidence: Established human efficacy for its labelled indications, supported by large randomised controlled trials and FDA review. SURMOUNT-5 supplies direct comparative evidence against semaglutide, although it was open-label and industry funded. Dedicated obesity cardiovascular-outcomes research remains ongoing.
Safety and known cautions
Prescription-only. Nausea, diarrhoea, vomiting and constipation are common. The US label includes a boxed warning about thyroid C-cell tumours seen in rodents and contraindicates use with a personal or family history of medullary thyroid carcinoma or MEN2; it also warns about pancreatitis, gallbladder disease, kidney injury from dehydration and aspiration risk. Weight regain can follow withdrawal. Use only with the prescribing clinician.
Evidence at a glance
No single score, on purpose. The line beside each bar shows how much reported outcomes vary between studies.
Development stage
- Discovery
- Preclinical
- Phase 1
- Phase 2
- Phase 3
- Regulatory review
- ApprovedCurrent