Obesity evidence dossier
Zepbound (tirzepatide)
The strongest approved mainstream benchmark for many patients, especially when weight-loss magnitude is the primary goal.
Total weight loss
20.9%
SURMOUNT-1 · 15 mg · week 72 · Includes treatment stops
Placebo-adjusted
17.8%
Difference from placebo in the same study when reported.
Study context
GIP/GLP-1 receptor agonist/Adults with obesity or overweight, without diabetes/2539 participants across the study/72-week endpoint
Baseline: See the source for enrollment criteria
Ranked result & calculation
SURMOUNT-1 · 15 mg · 72 weeks
Adults with obesity or overweight, without diabetes. 2,539 participants across the study (not this dose arm alone).
Includes treatment stops. Treatment-policy results estimate outcomes regardless of stopping treatment.
- Average weight loss
- 20.9%
- Placebo group
- 3.1% loss
- Beyond placebo
- 17.8 percentage points (arm subtraction)
- Stopped due to adverse events
- Not verified for this result
Score: 70% × 84.3 total-loss points + 30% × 82.1 beyond-placebo points = 84/100, rounded. Conversion scales
Alternative analysis assuming continued treatment: 22.5% total loss. This is not the result used for the headline score. Alternative analysis source ↗
SURMOUNT-1, NEJM ↗Phase 3 · Journal article · Reviewed 2026-09-21
Evidence
Benchmark read
SURMOUNT-1: Includes treatment stops.
Diabetes data
SURMOUNT-2 in type 2 diabetes showed lower average weight loss than SURMOUNT-1, which is expected and should be compared within the diabetes population.
Approved incretin anchor
Visceral fat
Included on the body-composition page as an approved incretin comparator, not as a targeted visceral-fat program.
Safety
Side effects and cautions
Discontinuation read
Adverse-event discontinuation has not been verified for this result.
Common side effects
Common adverse reactions include nausea, diarrhea, vomiting, constipation, abdominal pain, dyspepsia, injection-site reactions, fatigue, hypersensitivity reactions, burping, hair loss, and reflux.
Main cautions
Label warnings include thyroid C-cell tumor risk, pancreatitis, gallbladder disease, hypoglycemia with insulin or insulin secretagogues, acute kidney injury, severe gastrointestinal disease, and hypersensitivity. The suicidal-behavior-and-ideation warning was removed from the US label in February 2026.
Upcoming catalyst
What to watch next
Ongoing label-expansion work and real-world durability data, including cardiometabolic and sleep-apnea use.
Linked clinical trials
Trials in the saddl3 obesity snapshot
Non-diabetic obesity studies are prioritized; diabetes and healthy-volunteer studies remain visible and labeled.
NCT06588296
Phase 3
Ixekizumab Concomitantly Administered With Tirzepatide in Adults With Psoriatic Arthritis and Obesity or Overweight
Eli Lilly and Company
Non-diabetic obesity
Jan 21, 2026
NCT06588283
Phase 3
Ixekizumab Concomitantly Administered With Tirzepatide in Adults With Moderate-to-Severe Plaque Psoriasis and Obesity or Overweight
Eli Lilly and Company
Non-diabetic obesity
Jan 20, 2026
NCT05556512
Phase 3
A Study of Tirzepatide (LY3298176) on the Reduction on Morbidity and Mortality in Adults With Obesity
Eli Lilly and Company
Non-diabetic obesity
Jan 12, 2026
NCT06075667
Phase 3
A Study of Tirzepatide (LY3298176) Once Weekly in Adolescent Participants Who Have Obesity or Overweight With Weight-Related Comorbidities
Eli Lilly and Company
Non-diabetic obesity
Jun 25, 2025
NCT06662383
Phase 3
A Study of Retatrutide (LY3437943) Compared to Tirzepatide (LY3298176) in Adults Who Have Obesity
Eli Lilly and Company
Non-diabetic obesity
Apr 27, 2025
NCT06937086
Phase 3
Mirikizumab Administered at the Same Time as Tirzepatide in Adult Participants With Moderately to Severely Active Ulcerative Colitis and Obesity or Overweight: Phase 3b Study
Eli Lilly and Company
Non-diabetic obesity
Mar 24, 2026
NCT06937099
Phase 3
Mirikizumab and Tirzepatide Administered in Adult Participants With Moderately to Severely Active Crohn's Disease and Obesity or Overweight
Eli Lilly and Company
Non-diabetic obesity
Mar 24, 2026
NCT06439277
Phase 3
A Study of Tirzepatide in Adolescents With Obesity and Weight-Related Comorbidities (SURMOUNT-ADOLESCENTS-2)
Eli Lilly and Company
Non-diabetic obesity
Mar 24, 2026
NCT06047548
Phase 3
A Study of LY3298176 (Tirzepatide) For the Maintenance of Body Weight Reduction in Participants Who Have Obesity or Overweight With Weight-Related Comorbidities
Eli Lilly and Company
Non-diabetic obesity
Mar 25, 2026
NCT06131437
Phase 3
A Research Study to See How Well CagriSema Compared to Tirzepatide Helps People With Obesity Lose Weight
Novo Nordisk A/S
Non-diabetic obesity
Feb 6, 2026
NCT05822830
Phase 3
A Study of Tirzepatide (LY3298176) in Participants With Obesity or Overweight With Weight Related Comorbidities
Eli Lilly and Company
Non-diabetic obesity
Nov 26, 2025
NCT04847557
Phase 3
A Study of Tirzepatide (LY3298176) in Participants With Heart Failure With Preserved Ejection Fraction (HFpEF) and Obesity: The SUMMIT Trial
Eli Lilly and Company
Non-diabetic obesity
Aug 20, 2025