Phase 3 · Tirzepatide

SURMOUNT-1 trial results

Efficacy and Safety of Tirzepatide Once Weekly in Participants Without Type 2 Diabetes Who Have Obesity or Are Overweight With Weight- Related Comorbidities: A Randomized, Double-Blind, Placebo-Controlled Trial (SURMOUNT-1)

Percent Change From Baseline in Body Weight (Primary Treatment Period) (percent change), Baseline, Week 72. Placebo: -2.4; 5 mg Tirzepatide: -16.0; 10 mg Tirzepatide: -21.4; 15 mg Tirzepatide: -22.5.

Participants: 2,539
Status: completed
Completed: 2024-07-06
Sponsor: Eli Lilly and Company

As posted on ClinicalTrials.gov (NCT04184622), updated at source Jul 24, 2025. Read again whenever the registry updates it. Registry figures can differ from a published paper, which may use another analysis.

Primary outcome

What SURMOUNT-1 measured first

Percent Change From Baseline in Body Weight (Primary Treatment Period)percent change · Baseline, Week 72 · least squares mean

Placebon=635	5 mg Tirzepatiden=623	10 mg Tirzepatiden=629	15 mg Tirzepatiden=625
-2.4(0.40)	-16.0(0.39)	-21.4(0.39)	-22.5(0.39)

Percentage of Participants Who Achieve ≥5% Body Weight Reduction (Primary Treatment Period)Percentage of Participants · Week 72 · number

Placebon=635	5 mg Tirzepatiden=623	10 mg Tirzepatiden=629	15 mg Tirzepatiden=625
27.87	89.41	96.18	96.32

Side effects by arm

Side effects in SURMOUNT-1

Percent of participants affected, Baseline up to Week 193. The most common events the registry lists.

Event	Placebo	5 mg Tirzepatide	10 mg Tirzepatide	15 mg Tirzepatide
Any serious event	8.2%	9%	9.4%	7.9%
Nausea	9.8%	25.4%	34.1%	31.9%
Diarrhoea	7.9%	20.3%	22.5%	23.7%
Covid-19	16.5%	20.2%	20.1%	17.9%
Constipation	5.9%	17.9%	18.4%	12.7%
Vomiting	1.9%	9.2%	11.6%	12.9%
Decreased appetite	3.4%	9.5%	11.8%	8.7%
Dyspepsia	4.8%	9.4%	10.1%	11.7%
Headache	7.3%	7.5%	8%	7%
Abdominal pain	3.7%	6%	6%	5.2%
Urinary tract infection	5.9%	4.8%	6%	4.4%
Alopecia	1.1%	5.2%	5%	5.9%
Dizziness	2.5%	4.9%	5.8%	4.3%
Injection site reaction	0.3%	2.9%	5.7%	4.6%
Eructation	0.6%	3.8%	5.5%	5.6%
Type 2 diabetes mellitus	5.6%	0.8%	1.4%	0.6%
Gastrooesophageal reflux disease	2.5%	4.9%	4.4%	5.4%
Back pain	4%	4.9%	4.7%	5.4%
Upper respiratory tract infection	4.7%	5.1%	4.7%	4.8%
Arthralgia	3.4%	5.1%	3.1%	4%

Secondary outcomes

What else it measured

Change From Baseline in Body Weight (Pooled Doses of Tirzepatide 10 mg and 15 mg) - Primary Treatment Periodkilograms · Baseline, Week 20 · least squares mean

Placebon=635	Pooled 10 mg/15 mg Tirzepatiden=1,254
-2.5(0.22)	-13.2(0.16)

Percentage of Participants Who Achieve ≥10% Body Weight Reduction (Primary Treatment Period)Percentage of Participants · Week 72 · number

Placebon=635	5 mg Tirzepatiden=623	10 mg Tirzepatiden=629	15 mg Tirzepatiden=625
13.54	73.35	85.85	90.08

Percentage of Participants Who Achieve ≥15% Body Weight Reduction (Primary Treatment Period)Percentage of Participants · Week 72 · number

Placebon=635	5 mg Tirzepatiden=623	10 mg Tirzepatiden=629	15 mg Tirzepatiden=625
5.98	50.24	73.61	78.24

Percentage of Participants Who Achieve ≥20% Body Weight Reduction (Primary Treatment Period)Percentage of Participants · Week 72 · number

Placebon=635	5 mg Tirzepatiden=623	10 mg Tirzepatiden=629	15 mg Tirzepatiden=625
1.26	31.62	55.48	62.88

Change From Baseline in Waist Circumference (Primary Treatment Period)centimeters · Baseline, Week 72 · least squares mean

Placebon=634	5 mg Tirzepatiden=622	10 mg Tirzepatiden=629	15 mg Tirzepatiden=625
-3.4(0.42)	-14.6(0.41)	-19.4(0.41)	-19.9(0.41)

Change From Baseline in Short Form Survey-36 Version 2 (SF-36v2) Acute Form Physical Functioning Domain Score at Week 72 (Pooled Doses of Tirzepatide 10 mg and 15 mg) - Primary Treatment Periodscore on a scale · Baseline, Week 72 · least squares mean

Placebon=482	Pooled 10 mg/15 mg Tirzepatiden=1,080
1.7(0.27)	4.0(0.18)

Percent Change From Baseline in Triglycerides (Pooled Doses of Tirzepatide 5 mg, 10 mg and 15 mg) - Primary Treatment Periodpercent change · Baseline, Week 72 · mean

Placebon=612	Pooled 5 mg/10 mg/15 mg Tirzepatiden=1,822
-6.3(1.55)	-27.6(0.66)

Percent Change From Baseline in Total Cholesterol (Pooled Doses of Tirzepatide 5 mg, 10 mg and 15 mg) - Primary Treatment Periodpercent change · Baseline, Week 72 · mean

Placebon=612	Pooled 5 mg/10 mg/15 mg Tirzepatiden=1,822
-1.11(0.695)	-5.97(0.364)

Percent Change From Baseline in High-Density Lipoprotein (HDL) Cholesterol at Week 72 (Pooled Doses of Tirzepatide 5 mg, 10 mg and 15 mg) - Primary Treatment Periodpercent change · Baseline, Week 72 · mean

Placebon=581	Pooled 5 mg/10 mg/15 mg Tirzepatiden=1,764
0.25(0.757)	7.92(0.447)

Change From Baseline in Systolic Blood Pressure (SBP) (Pooled Doses of Tirzepatide 5 mg, 10 mg and 15 mg) - Primary Treatment Periodmillimeter of mercury (mmHg) · Baseline, Week 72 · least squares mean

Placebon=634	Pooled 5 mg/10 mg/15 mg Tirzepatiden=1,878
-1.3(0.48)	-8.1(0.27)

Percent Change From Baseline in Fasting Insulin (Pooled Doses of Tirzepatide 5 mg, 10 mg and 15 mg) - Primary Treatment Periodpercent change · Baseline, Week 72 · mean

Placebon=590	Pooled 5 mg/10 mg/15 mg Tirzepatiden=1,779
-9.7(2.60)	-46.9(0.83)

Percent Change From Baseline in Body Weight (Primary and Additional Treatment Periods : Participants With Prediabetes at Randomization)percent change · Baseline, Week 176 · least squares mean

Placebon=264	5 mg Tirzepatiden=245	10 mg Tirzepatiden=260	15 mg Tirzepatiden=249
-2.1(0.78)	-15.4(0.74)	-19.9(0.72)	-22.9(0.73)

The trial

How SURMOUNT-1 was run

This is a study of tirzepatide in participants with overweight and obesity. The main purpose is to learn more about how tirzepatide affects body weight. The study has two phases: A main phase and an extension phase. The main phase of the study will last 72 weeks. Participants with prediabetes will continue in the extension for another 2 years.

Placebo: * Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received once weekly (QW) subcutaneous (SC) doses of a matching placebo, administered over a period of 72 weeks. * Additional Treatment Period (Week 72-Week 176): At week 72, only participants who had prediabetes at the time of randomization and had completed the primary treatment period continued receiving the placebo dose SC QW until week 176. * Safety Follow-up Period:...
5 mg Tirzepatide: * Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received QW SC doses of tirzepatide, starting at 2.5 milligrams (mg) and increasing by 2.5 mg every 4 weeks until reaching a dose of 5 mg, which was then maintained up to week 72. * Additional Treatment Period (Week 72-Week 176): At week 72, only participants who had prediabetes at the time of randomization and had completed the primary treatment period continued receiving...
10 mg Tirzepatide: * Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received QW SC doses of tirzepatide, starting at 2.5 mg and increasing by 2.5 mg every 4 weeks until reaching a dose of 10 mg, which was then maintained up to week 72. * Additional Treatment Period (Week 72-Week 176): At week 72, only participants who had prediabetes at the time of randomization and had completed the primary treatment period continued receiving the 10 mg...
15 mg Tirzepatide: * Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received QW SC doses of tirzepatide, starting at 2.5 mg and increasing by 2.5 mg every 4 weeks until reaching a dose of 15 mg, which was then maintained up to week 72. * Additional Treatment Period (Week 72-Week 176): At week 72, only participants who had prediabetes at the time of randomization and had completed the primary treatment period continued receiving the 15 mg...

Who could join the trial

Inclusion Criteria: * Body mass Index (BMI) ≥30 kilograms per square meter (kg/m²), or ≥27 kg/m² and previous diagnosis with at least one of the following comorbidities: hypertension, dyslipidemia, obstructive sleep apnea, cardiovascular disease * History of at least one unsuccessful dietary effort to lose body weight Exclusion Criteria: * Diabetes mellitus * Change in body weight greater than 5 kg within 3 months prior to starting study * Obesity induced by other endocrinologic disorders or monogenetic or syndromic forms of obesity * History of pancreatitis * Family or personal history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN-2) * History of significant active or unstable major depressive disorder (MDD) or other severe psychiatric disorder within the last 2 years * Any lifetime history of a suicide attempt

Published papers

Papers from SURMOUNT-1

Trial averages do not predict what one person will experience. Results are shown as the registry posts them, without interpretation.

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