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Benefits and uses

Zepbound benefits and uses

FDA has approved Zepbound for weight reduction and long-term weight maintenance in adults with obesity, or overweight with a related condition.1 It is also approved for moderate to severe obstructive sleep apnea in adults with obesity.1 In its largest 72-week trial, average weight loss was 15.0% to 20.9% by dose, against 3.1% on placebo.2

This page summarizes published sources for information only. It is not medical advice and does not tell anyone to use a product. Questions about your own health belong with a licensed clinician. For questions about an order or a product, contact us.

The two approved uses

The Zepbound benefits FDA has reviewed fall under two approved uses, each paired with a reduced-calorie diet and more physical activity.113

  • Weight reduction and maintenance: adults with obesity (BMI 30 or more), or with overweight (BMI 27 or more) and at least one weight-related condition.114
  • Obstructive sleep apnea (OSA): moderate to severe OSA in adults with obesity.112

Each result below names its trial design and size.

Weight reduction

SURMOUNT-1 (label Study 1)

SURMOUNT-1 was a phase 3, double-blind, placebo-controlled trial in 2,539 adults with obesity, or overweight plus a weight-related condition, and no type 2 diabetes.215 Women made up 68% of participants, and treatment lasted 72 weeks.2

Result at 72 weeks 5 mg 10 mg 15 mg Placebo
Average weight loss2 15.0% 19.5% 20.9% 3.1%
Lost at least 5% of body weight2 85.1% 88.9% 90.9% 34.5%
Lost at least 10%2 68.5% 78.1% 83.5% 18.8%
Lost at least 15%2 48.0% 66.6% 70.6% 8.8%
Lost at least 20%2 30.0% 50.1% 56.7% 3.1%
Waist reduction2 14.0 cm 17.7 cm 18.5 cm 4.0 cm

Systolic blood pressure fell 6.6 to 7.7 mmHg, against 1.0 mmHg on placebo.2 Triglycerides fell 21.2% to 29.1%, against 5.6%.2 The label notes that several of these results were not controlled for multiple testing.2 It also reports weight reduction regardless of age, sex, race, ethnicity, starting BMI and blood sugar status.2

Two more weight trials in the label

  • Adults with type 2 diabetes (Study 2; randomized, double-blind, placebo-controlled; 938 adults with a BMI of 27 or more; 72 weeks): average weight loss was 12.8% on 10 mg and 14.7% on 15 mg, against 3.2% on placebo.2 HbA1c fell 2.1 points on both doses, against 0.5 on placebo, from a starting level near 8.0%.2 Blood sugar control itself is a Mounjaro use, not an approved Zepbound use.116
  • After an intensive diet program (Study 3; randomized, placebo-controlled; 579 adults): participants first lost at least 5% of body weight, 6.9% on average, during 12 weeks of intensive diet and exercise.2 Over the next 72 weeks, Zepbound 10 or 15 mg produced a further 18.4% loss, while the placebo group gained 2.5%.2

Against semaglutide

SURMOUNT-5 was an open-label phase 3b trial in 751 adults with obesity and no type 2 diabetes.7 Over 72 weeks, average weight loss was 20.2% on tirzepatide (10 or 15 mg) and 13.7% on semaglutide (1.7 or 2.4 mg).7 Waist circumference fell 18.4 cm against 13.0 cm.7 Semaglutide 2.4 mg is a strength FDA lists for Wegovy.17

Keeping the weight off

SURMOUNT-4 was a phase 3 randomized withdrawal trial.318 After 36 weeks of open-label Zepbound, with an average loss of 20.9%, 670 adults were randomized to continue or switch to placebo.318

  • From week 36 to week 88, the placebo group's weight rose 14.0%, while the group that stayed on Zepbound lost a further 5.5%.3
  • Total loss over the 88 weeks was 25.3% with continued treatment and 9.9% after the switch.18
  • At week 88, 89.5% of those who stayed on treatment had kept at least 80% of their earlier loss, against 16.6% of those switched to placebo.18

Obstructive sleep apnea

SURMOUNT-OSA (label Studies 5 and 6) enrolled 469 adults with obesity and moderate to severe OSA for 52 weeks.1119 One trial included people not using positive airway pressure (PAP) therapy; the other included PAP users.11 Starting severity averaged about 50 events per hour on the apnea-hypopnea index (AHI), and 67% and 72% of participants were men.11

Result at 52 weeks Zepbound, no PAP Placebo, no PAP Zepbound, PAP users Placebo, PAP users
Drop in AHI, events per hour11 25.3 5.3 29.3 5.5
Drop in AHI, percent11 50.7% 3% 58.7% 2.5%
Remission or mild OSA without symptoms11 42.2% 15.9% 50.2% 14.3%
Weight loss11 17.7% 1.6% 19.6% 2.3%

Systolic blood pressure and high-sensitivity C-reactive protein (hsCRP) fell more than on placebo, and sleep-related patient-reported outcomes improved.1119

Results outside the approved uses

The findings below come from trials, but they are not approved Zepbound uses as of the August 2026 label.1

  • Diabetes prevention: a 3-year SURMOUNT-1 analysis followed 1,032 adults with obesity and prediabetes (phase 3).20 Type 2 diabetes was diagnosed in 1.3% on tirzepatide and 13.3% on placebo.20 Weight loss at 176 weeks was 12.3% to 19.7% by dose, against 1.3%.20
  • Heart failure: SUMMIT was a randomized, double-blind, placebo-controlled trial in 731 adults with obesity and heart failure with preserved ejection fraction.10 Over a median of 104 weeks, cardiovascular death or worsening heart failure occurred in 9.9% on tirzepatide against 15.3% on placebo (hazard ratio 0.62).10

Limits of the evidence

  • Lean mass falls too: the label reports greater fat mass loss than lean mass loss, so the weight lost is not fat alone.4
  • Maker-funded research: SURMOUNT-1, its 3-year analysis, SURMOUNT-OSA, SURMOUNT-5, SURPASS-2 and SUMMIT were all funded by Eli Lilly, the maker of Zepbound.1520197610
  • Lifestyle counseling was part of the trials: participants in the weight trials also received diet and activity counseling.2
  • Results depend on continued use: the SURMOUNT-4 authors concluded that stopping tirzepatide brought back a large share of the weight lost.18

Forms, storage and regulatory history are on What is Zepbound?. Risks are in Zepbound side effects and the label schedule in Zepbound dosage. For the same drug in diabetes, see Mounjaro benefits and uses; for brand comparisons, see Compare GLP-1 medicines.

More on Zepbound

  • Zepbound side effects

    Side effects of Zepbound as reported in labels, trials and published studies, with links to the full profile. Reviewed by a qualified reviewer.

  • Zepbound dosage

    Published dosing information for Zepbound from labels and studies, with its source, and why it is not advice for you.

Frequently asked questions

What is the average weight loss on Zepbound?

SURMOUNT-1, the largest trial in the label, ran for 72 weeks in adults without type 2 diabetes.215 Average weight loss was 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, against 3.1% on placebo.2 In adults with type 2 diabetes it was 12.8% on 10 mg and 14.7% on 15 mg, against 3.2% on placebo.2

How effective is Zepbound for weight loss?

On 15 mg in SURMOUNT-1, 90.9% of participants lost at least 5% of body weight by week 72, and 56.7% lost at least 20%.215 On placebo the shares were 34.5% and 3.1%.2 Keeping the loss depends on staying on treatment: in SURMOUNT-4, people switched to placebo after 36 weeks saw their weight rise 14.0% over the next 52 weeks.318

What does Zepbound do to the body to help lose weight?

Its active ingredient, tirzepatide, activates GIP and GLP-1 receptors, including receptors in brain areas that regulate appetite.4 The label explains that tirzepatide reduces how much people eat, likely through effects on appetite, and that body fat falls more than lean tissue.4 Stomach emptying also slows, most of all after the first dose.4

Does Zepbound work as well as Ozempic?

The closest evidence compares the active ingredients: tirzepatide in Zepbound and semaglutide in Ozempic.5 In SURPASS-2, an open-label trial, 1,879 adults with type 2 diabetes took tirzepatide or semaglutide 1 mg for 40 weeks.6 HbA1c fell 2.01 to 2.30 points on tirzepatide against 1.86, and weight loss was 1.9 to 5.5 kg greater.6 In SURMOUNT-5, adults with obesity lost 20.2% on tirzepatide against 13.7% on semaglutide 1.7 or 2.4 mg.7 See What is Ozempic?.

Is Zepbound good for the heart?

Zepbound is not FDA-approved to lower heart risk.1 The same drug, as Mounjaro, is approved to lower the risk of major cardiovascular events in high-risk adults with type 2 diabetes.8 In adults with obesity, the 15,374-person SURMOUNT-MMO outcomes trial is still running, with primary completion estimated for October 2027.9 The SUMMIT heart failure trial reported fewer events on tirzepatide, but heart failure is not an approved Zepbound use.101

Can Zepbound replace a CPAP machine?

The label does not say so: its sleep apnea trials did not evaluate whether, or when, people already using positive airway pressure (PAP) therapy could stop it.11 In the trial of PAP users, PAP was paused for 7 days before the main measurement.11 The approved use is moderate to severe obstructive sleep apnea in adults with obesity, together with a reduced-calorie diet and more physical activity.12

Written by D2C Peptides Editorial Team.

Pending qualified review.

Updated .

Sources

  1. Zepbound Prescribing Information, revised 08/2026 (NDA 217806/S-041): Section 1 Indications and Usage. Eli Lilly and Company; posted by U.S. Food and Drug Administration, 2026.
  2. Same source as 1: Section 14.1 Weight Reduction Studies 1, 2 and 3 (Tables 2 to 5).
  3. Same source as 1: Section 14.1 Randomized Withdrawal Study 4 (Table 6).
  4. Same source as 1: Sections 12.1 Mechanism of Action and 12.2 Pharmacodynamics.
  5. Drugs@FDA: NDA 209637, Ozempic (semaglutide) application overview. U.S. Food and Drug Administration, 2026.
  6. Frias JP et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). N Engl J Med 2021;385(6):503-515. PMID 34170647, doi:10.1056/NEJMoa2107519 (PubMed record). New England Journal of Medicine (record via NCBI PubMed E-utilities), 2021.
  7. Aronne LJ et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med 2025;393(1):26-36. PMID 40353578, doi:10.1056/NEJMoa2416394 (PubMed record). New England Journal of Medicine (record via NCBI PubMed E-utilities), 2025.
  8. Mounjaro Prescribing Information, revised 08/2026: Indications, cardiovascular risk reduction. Eli Lilly and Company; posted by U.S. Food and Drug Administration, 2026.
  9. ClinicalTrials.gov NCT05556512: SURMOUNT-MMO. U.S. National Library of Medicine (ClinicalTrials.gov), 2026.
  10. Packer M et al. Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity (SUMMIT). N Engl J Med 2025;392:427-437. PMID 39555826, doi:10.1056/NEJMoa2410027 (PubMed record). New England Journal of Medicine (record via NCBI PubMed E-utilities), 2025.
  11. Same source as 1: Section 14.2 Obstructive Sleep Apnea Studies 5 and 6 (Tables 8 and 9).
  12. FDA Approves First Medication for Obstructive Sleep Apnea (news release, December 20, 2024). U.S. Food and Drug Administration, 2024.
  13. Same source as 1: Section 2.4 Important Administration Instructions.
  14. FDA Approves New Medication for Chronic Weight Management (news release, November 8, 2023). U.S. Food and Drug Administration, 2023.
  15. Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med 2022;387(3):205-216. PMID 35658024, doi:10.1056/NEJMoa2206038 (PubMed record). New England Journal of Medicine (record via NCBI PubMed E-utilities), 2022.
  16. Same source as 8: revised 08/2026 (NDA 215866/S-044, S-045): Indications, glycemic control.
  17. Drugs@FDA: NDA 215256, Wegovy (semaglutide) application overview. U.S. Food and Drug Administration, 2026.
  18. Aronne LJ et al. Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial. JAMA 2024;331(1):38-48. PMID 38078870, doi:10.1001/jama.2023.24945 (PubMed record). JAMA (record via NCBI PubMed E-utilities), 2024.
  19. Malhotra A et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA). N Engl J Med 2024;391(13):1193-1205. PMID 38912654, doi:10.1056/NEJMoa2404881 (PubMed record). New England Journal of Medicine (record via NCBI PubMed E-utilities), 2024.
  20. Jastreboff AM et al. Tirzepatide for Obesity Treatment and Diabetes Prevention (SURMOUNT-1, 3-year). N Engl J Med 2025;392(10):958-971. PMID 39536238, doi:10.1056/NEJMoa2410819 (PubMed record). New England Journal of Medicine (record via NCBI PubMed E-utilities), 2025.