What Is Zepbound Approved For? Label Indications, Per the Research

The short answer

Zepbound is a prescription medicine; its active ingredient is tirzepatide, a once-weekly injectable that acts at both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. In the United States, the Food and Drug Administration approved Zepbound in November 2023 for chronic weight management in adults with obesity (body mass index of 30 kg/m² or greater) or overweight (body mass index of 27 kg/m² or greater) with at least one weight-related condition, as an adjunct to a reduced-calorie diet and increased physical activity. In December 2024 the agency approved a second indication: moderate-to-severe obstructive sleep apnea in adults with obesity.

Those two indications define what the product is approved for. Everything else discussed in the tirzepatide literature — glycaemic control in type 2 diabetes (which belongs to a separate tirzepatide-branded product), progression to diabetes in people with prediabetes, liver outcomes, muscle and fat composition — appears in this page as research or guideline material, clearly separated from the label. This page is for educational purposes only and is not medical advice; consult a licensed physician about any medical condition, medicine or treatment decision.

Approved indications at a glance

Brand names and approved wording differ between countries, and tirzepatide is marketed under more than one brand name depending on the indication and the jurisdiction. The authoritative text for any given market is the locally approved prescribing information, not a summary page.

Indication 1: chronic weight management

The trial that anchored the approval

SURMOUNT-1 enrolled 2,539 adults with obesity, or with overweight plus at least one weight-related complication and without diabetes, and the study assigned them to once-weekly tirzepatide 5 mg, 10 mg or 15 mg or placebo for 72 weeks, reporting mean weight reductions of 15.0%, 19.5% and 20.9% respectively, compared with 3.1% with placebo (PMID 35658024). Researchers in that trial described gastrointestinal events — nausea, diarrhoea and constipation — as the most common adverse events, mostly mild to moderate and concentrated during dose escalation (PMID 35658024).

Adults who also have type 2 diabetes

SURMOUNT-2 studied adults with obesity and type 2 diabetes over 72 weeks and reported mean weight reductions of 12.8% with 10 mg and 14.7% with 15 mg, versus 3.2% with placebo (PMID 37385275). Type 2 diabetes is one of the weight-related conditions named in the weight-management indication; that does not make glycaemic control itself a Zepbound indication, a distinction covered further below.

Maintenance after initial weight reduction

SURMOUNT-4 used a 36-week open-label lead-in followed by randomised withdrawal, and the study reported that participants who continued tirzepatide through week 88 had an additional mean weight reduction of 5.5%, while those switched to placebo regained a mean of 14.0% (PMID 38078870). Researchers framed this as evidence on what happens when treatment is continued versus stopped, which is why the label describes chronic — that is, ongoing — weight management.

Evidence in other populations

SURMOUNT-CN randomised Chinese adults with obesity to tirzepatide or placebo for 52 weeks and reported significantly greater percentage weight reduction with tirzepatide than with placebo at the end of the trial (PMID 38819983). Trials of this kind inform regional regulatory submissions; whether an approval exists in a particular country is a separate question answered by that country's regulator.

Indication 2: moderate-to-severe obstructive sleep apnea with obesity

The second approved indication rests on SURMOUNT-OSA, a programme of two 52-week randomised trials in adults with moderate-to-severe obstructive sleep apnea and obesity — one in participants not using positive airway pressure therapy and one in participants using it — in which researchers reported significantly greater reductions in the apnea–hypopnea index with tirzepatide than with placebo, alongside greater reductions in body weight (PMID 38912654). The study reported gastrointestinal adverse events as the most frequent, consistent with the pattern described across the wider tirzepatide programme (PMID 38912654).

The approved wording ties the indication to adults who have both obstructive sleep apnea and obesity. It does not extend to sleep apnea in people without obesity, and it does not describe the medicine as a replacement for any other therapy; questions about how it fits alongside existing sleep-apnea care are clinical questions for a treating physician.

What is studied but not a Zepbound indication

Glycaemic control in type 2 diabetes

Tirzepatide has a large type 2 diabetes evidence base, but in the United States that indication sits with a separately branded tirzepatide product, not with Zepbound. SURPASS-2 compared tirzepatide with semaglutide 1 mg once weekly over 40 weeks and reported greater reductions in glycated haemoglobin with tirzepatide (PMID 34170647). SURPASS-3 compared once-weekly tirzepatide with once-daily insulin degludec as add-on to metformin with or without an SGLT2 inhibitor over 52 weeks and reported greater glycated haemoglobin and weight reductions with tirzepatide (PMID 34370970). SURPASS-5 added tirzepatide or placebo to titrated insulin glargine and reported significantly greater improvement in glycaemic control with tirzepatide at 40 weeks (PMID 35133415). A systematic review and meta-analysis of the tirzepatide diabetes programme reported reductions in glycated haemoglobin and body weight relative to comparators, with gastrointestinal adverse events more common on tirzepatide (PMID 35579691).

Prevention of type 2 diabetes

An extension of SURMOUNT-1 followed adults with obesity or overweight and prediabetes for 176 weeks and reported a lower incidence of progression to type 2 diabetes with tirzepatide than with placebo, together with sustained weight reduction (PMID 39536238). That is a trial finding in a defined study population. Diabetes prevention is not written into the approved indications described above.

Metabolic dysfunction-associated steatotic liver disease

The EASL–EASD–EASO clinical practice guidelines on the management of metabolic dysfunction-associated steatotic liver disease set out how weight management and metabolic risk-factor control sit within MASLD care and reviewed the pharmacological options discussed for people with obesity and steatotic liver disease (PMID 38851997). Guideline discussion is not the same as a regulatory indication, and the guidelines are written for clinicians rather than as instructions for individuals.

Body composition

A post-hoc magnetic resonance imaging analysis of the SURPASS-3 trial examined muscle composition in people with type 2 diabetes and reported changes in muscle volume and muscle fat alongside the weight reduction observed with tirzepatide (PMID 40318682). Post-hoc analyses are exploratory by design and generate questions rather than settle them.

Adverse Events in the Pivotal Trials: What Studies Report

Across the published programme, the most frequently reported adverse events were gastrointestinal. In SURMOUNT-1 researchers reported nausea, diarrhoea and constipation as the most common events, predominantly mild to moderate and most frequent during dose escalation, with discontinuation for adverse events occurring in a minority of participants (PMID 35658024). SURMOUNT-2 reported a similar gastrointestinal pattern in adults with obesity and type 2 diabetes (PMID 37385275), and the SURMOUNT-OSA trials reported gastrointestinal events as the most common with tirzepatide over 52 weeks (PMID 38912654). The diabetes meta-analysis likewise reported a higher frequency of gastrointestinal adverse events with tirzepatide than with comparators (PMID 35579691).

Trial safety reporting reflects selected populations under protocol monitoring. The approved labelling carries the full safety profile, including boxed warnings, contraindications and precautions, and that document — read with a prescribing clinician — is the relevant source for any individual.

Why the distinction between approved and investigational matters

• Approval is indication-specific. A regulator reviews a defined population, endpoint and evidence package. Zepbound's two approvals describe chronic weight management and obstructive sleep apnea with obesity; neither approval converts every tirzepatide trial into a label claim.
• Brand names track indications. The same molecule can carry different brand names for different approved uses, which is why the diabetes trials described above sit outside Zepbound's label.
• Off-label prescribing exists but is not approval. Clinicians may prescribe outside the labelled indication in some jurisdictions; that remains a clinical judgement made case by case, not a regulatory endorsement.
• Guidelines and trials move faster than labels. A finding reported in a journal, such as reduced progression to type 2 diabetes over 176 weeks (PMID 39536238), may never become a labelled indication, or may do so only after further regulatory review.

Questions a clinician is positioned to answer

1. Which approved indication, if any, applies to a particular person's diagnosis and measurements.
2. How the contraindications, warnings and monitoring requirements in the current label apply to an individual's history.
3. How the medicine interacts with other prescriptions and existing conditions.
4. What the published trial evidence does and does not say about people outside the enrolled populations.
5. What follow-up and assessment would accompany any treatment decision.

This page summarises published literature and publicly documented regulatory status for educational purposes only. It is not medical advice, it does not describe how any medicine should be used, and every question about suitability, initiation, continuation or discontinuation belongs with a licensed prescribing clinician.

References

• Tirzepatide Once Weekly for the Treatment of Obesity (The New England Journal of Medicine, 2022)
• Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial (Lancet, 2023)
• Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial (JAMA, 2024)
• Tirzepatide for Weight Reduction in Chinese Adults With Obesity: The SURMOUNT-CN Randomized Clinical Trial (JAMA, 2024)
• Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (The New England Journal of Medicine, 2024)
• Tirzepatide for Obesity Treatment and Diabetes Prevention (The New England Journal of Medicine, 2025)
• Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (The New England Journal of Medicine, 2021)
• Once-weekly tirzepatide versus once-daily insulin degludec as add-on to metformin with or without SGLT2 inhibitors in patients with type 2 diabetes (SURPASS-3) (Lancet, 2021)
• Effect of Subcutaneous Tirzepatide vs Placebo Added to Titrated Insulin Glargine on Glycemic Control in Patients With Type 2 Diabetes: The SURPASS-5 Randomized Clinical Trial (JAMA, 2022)
• Management of type 2 diabetes with the dual GIP/GLP-1 receptor agonist tirzepatide: a systematic review and meta-analysis (Diabetologia, 2022)
• Tirzepatide and muscle composition changes in people with type 2 diabetes (SURPASS-3 MRI): a post-hoc analysis of a randomised, open-label, parallel-group, phase 3 trial (The Lancet Diabetes & Endocrinology, 2025)
• EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD) (Journal of Hepatology, 2024)