Zepbound weight loss chart: SURMOUNT trial results
In SURMOUNT-1, the main 72-week trial in 2,539 adults without diabetes, average weight changed −15.0%, −19.5% and −20.9% with Zepbound 5, 10 and 15 mg, against −3.1% with placebo, as reported in the FDA label. Adults with type 2 diabetes lost less (−12.8% and −14.7% at 10 and 15 mg in SURMOUNT-2). These are trial averages and do not predict any one person’s result.
Checked against the FDA label and cited trials on
Peptide Library is an independent educational resource. It is not affiliated with, sponsored or endorsed by Novo Nordisk or Eli Lilly; Ozempic, Wegovy, Mounjaro and Zepbound are trademarks of their owners and are named only to identify the products. This page summarizes FDA-approved prescribing information and published trials. It is not individual medical advice: dosing and any change to it are decided with a prescriber.
The product
Zepbound (tirzepatide)
Manufacturer
Eli Lilly
Form
Once-weekly injection: single-dose pens or vials (2.5 to 15 mg), multi-dose KwikPen or vial
FDA-approved uses
Reducing excess body weight and keeping it off long term in adults with obesity, or overweight with a weight-related condition
Moderate to severe obstructive sleep apnea in adults with obesity
Boxed warning
Risk of thyroid C-cell tumors: tirzepatide caused thyroid C-cell tumors in rats; whether it does in humans is unknown. Contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2.
Group averages from selected trial populations, each beside its own trial’s comparator. They do not predict any one person’s result, and figures from different trials are not compared with each other.
People with type 2 diabetes lost less weight than people without it in both tirzepatide and semaglutide programs; compare SURMOUNT-1 and SURMOUNT-2 only as separate trials.
Adults who first lost at least 5% in a 12-week intensive lifestyle program
Randomized
579
Duration
72 weeks after randomization
Comparator
Placebo
Reported results
SURMOUNT-3: Mean % change in body weight, Week 72 (from randomization)Label section 14: all randomized patients, missing data imputed from retrieved dropouts
SURMOUNT-3: Mean % change in body weight at Week 72 (from randomization), by arm
Adults who lost weight on 36 weeks of open-label Zepbound, then were randomized to continue or switch to placebo
Randomized
670
Duration
Week 36 to week 88
Comparator
Placebo (treatment withdrawn)
Reported results
SURMOUNT-4 (stopping vs continuing): Mean % change in body weight from week 36, Week 88Label section 14: all randomized patients, missing data imputed from retrieved dropouts
SURMOUNT-4 (stopping vs continuing): Mean % change in body weight from week 36 at Week 88, by arm
Each panel is one trial, with every dose beside that trial’s placebo group. The trials enrolled different people for different lengths of time, so a figure from one trial is not compared with a figure from another. SURMOUNT-3 and SURMOUNT-4 measure from a later starting point (after a lifestyle program, or after 36 weeks of treatment), and SURMOUNT-4 shows what happened when treatment was stopped.
Figures are the label’s least-squares means for all randomized participants, with missing data imputed from people who stopped treatment (retrieved dropouts). The label’s section 14 is the source for every number unless the panel says otherwise.
Side effects in the label
In the pooled SURMOUNT-1 and SURMOUNT-2 data, nausea was reported in 25%, 29% and 28% on 5, 10 and 15 mg vs 8% on placebo; diarrhea 19%, 21% and 23% vs 8%; vomiting 8%, 11% and 13% vs 2%; constipation 17%, 14% and 11% vs 5%. Stopping because of adverse reactions: 4.8%, 6.3% and 6.7% vs 3.4%.
Zepbound compared with semaglutide
The one randomized head-to-head trial, SURMOUNT-5 (NEJM 2025, open-label, 751 adults with obesity, 72 weeks), reported −20.2% with tirzepatide at the maximum tolerated dose (10 or 15 mg) vs −13.7% with semaglutide at the maximum tolerated dose (1.7 or 2.4 mg). It was funded by Eli Lilly and is not part of either label.
Questions
How much weight do people lose on Zepbound?
+
In SURMOUNT-1 the average change at 72 weeks was −15.0% (5 mg), −19.5% (10 mg) and −20.9% (15 mg) vs −3.1% with placebo, per the FDA label. Individual results vary widely and the averages do not predict any one person’s.
What happens if you stop Zepbound?
+
In SURMOUNT-4, people switched to placebo after 36 weeks changed by an average of +14.0% from their week-36 weight by week 88, while those who continued changed by −5.5%.
Is Zepbound the same as Mounjaro?
+
Both contain tirzepatide, but they are separate FDA-approved products with different indications: Zepbound for weight management and sleep apnea, Mounjaro for type 2 diabetes. See Mounjaro vs Zepbound.
Peptide Library