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SURMOUNT-3: Tirzepatide After a Lifestyle Run-In

Last verified May 2026 · 3 · Finished; headline results reported 2023 · NCT04657016

By Ruth Calder · Enforcement Editor
Editorially reviewed & fact-checked against primary sources · How we verify contentLast reviewed

The most common objection to these drugs is that people should try diet and exercise first, and the most common defense is that they usually have. SURMOUNT-3 is the trial that speaks to both positions, because everyone in it did the lifestyle work and did it successfully enough to enter the randomized phase. What happened next — continued substantial loss on drug, gradual regain on placebo — is a fairly direct measurement of what the medication contributes to someone who has already done everything they were told to do.

Enrollment
579
Duration
A 12-week intensive lifestyle lead-in, then 72 weeks of randomized treatment — 84 weeks in all, with side-effect monitoring to week 76
Drug
Tirzepatide
Population
Adults 18 and over with a BMI of 30 or more — or 27 or more if a weight-related condition came with it. Diabetes ruled people out. So did previous pancreatitis, medullary thyroid cancer or MEN-2 in the family or the person, major depression inside two years, and a suicide attempt at any time in life. ⚠ 806 people started the 12-week lifestyle program and only the 579 who lost at least 5% went forward — so 28% never reached randomization, and everyone in the trial proper had already proved they could lose weight without a drug. At that point they averaged 101.87 kg, 63% women, 86% white, mean age 45.6.

Primary endpoint

How much MORE weight came off in the 72 weeks after the lifestyle program had already worked

Treatment arm

-18.4% (SE 0.7)

Comparator

+2.5% (SE 1.0)

Treatment difference: Estimated treatment difference -20.8 percentage points (95% CI -23.2 to -18.5; P<0.001)

⚠ Read the starting line carefully: this is measured from randomization, not from the beginning. Add the roughly 7% already lost during the lead-in and the drug group finished somewhere in the mid-twenties overall, against a net 3 to 4% for placebo. ⛔ What you cannot do is add 18.4% to another trial's 20.9% — different starting points, and nobody in either trial lost that much.

Secondary endpoints

EndpointTreatmentComparatorDifference
Kept losing — at least another 5% after the lifestyle phase

Nearly nine in ten on the drug kept going, against roughly one in six on placebo.

87.5% (SE 2.2)16.5% (SE 3.0)Odds ratio 34.6 (95% CI 19.2 to 62.6; P<0.001)
Still holding most of what the lifestyle program had achieved, a year and a half later

★ The single most important row on this page, and the one insurers should read. Without the drug, only about a third of people who had successfully lost weight still held most of it. With it, essentially everyone did — 98.6%.

98.6%37.8%Logistic regression favored tirzepatide; P<0.001
Lost at least another tenth

88.0% against 4.8%. The gap widens sharply as the target rises.

88.0%4.8%P<0.001
Lost at least another 15%

Nearly three quarters against 2.1%.

73.9%2.1%P<0.001
Lost at least another fifth

★ Over half shed another fifth beyond what they had already lost. On placebo, 1% did.

54.9%1.0%P<0.001
Inches off the waist

Nearly 17 cm off on the drug while the placebo group's waist grew slightly.

-16.8 cm (SE 0.56)+1.1 cm (SE 0.58)Estimated treatment difference roughly -17.9 cm
Top blood-pressure number

⚠ Note the direction on placebo: blood pressure went back up as the weight came back, which is what makes the gap here over 10 points. Regain is not a neutral event.

-5.8 mmHg (SE 0.73)+4.4 mmHg (SE 0.76)Estimated treatment difference roughly -10.2 mmHg
Triglycerides, a blood fat

Down about a quarter on the drug, up slightly on placebo.

-25.8% (SE 1.61)+3.0% (SE 2.34)Estimated treatment difference roughly -29 percentage points
Total cholesterol

Down modestly on the drug, up about 5% on placebo — again, the regain doing the work.

-3.0% (SE 0.97)+5.2% (SE 1.11)Estimated treatment difference roughly -8 percentage points
Three-month average blood sugar

⚠ Nobody here had diabetes, so this shifts within the normal-to-prediabetic band.

-0.46% (SE 0.020)+0.01% (SE 0.022)Estimated treatment difference roughly -0.47 percentage points
Blood sugar after an overnight fast

Down about 9 mg/dL on the drug, up slightly on placebo.

-8.8 mg/dL (SE 0.82)+2.4 mg/dL (SE 0.86)Estimated treatment difference roughly -11.2 mg/dL

Adverse events

EventTreatment rateComparator rate
Nausea

The leading complaint, mostly mild to moderate, and bunched into the 20 weeks while the dose was being raised.

39.7% (114/287)14.0% (41/292)
Diarrhea

Roughly three times the placebo rate.

31.0% (89/287)9.2% (27/292)
Constipation

About 23% against 7% on placebo.

23.0% (66/287)6.8% (20/292)
Vomiting

★ The widest gap of any stomach effect — 18.1% against 1.4%. If one side effect is going to decide whether you stay on this drug, it is likely this one.

18.1% (52/287)1.4% (4/292)
Reaction where the injection went in

About one in nine, against 1% on placebo.

11.1% (32/287)1.0% (3/292)
Stomach pain

Around four times the placebo rate.

10.5% (30/287)2.4% (7/292)
Indigestion

About 9% against 3% on placebo.

9.4% (27/287)3.1% (9/292)
Loss of appetite

Recorded as a side effect, though it is the mechanism rather than a complication.

9.4% (27/287)4.1% (12/292)
Headache

Barely above the placebo rate — one of the few complaints that is not really about the drug.

9.4% (27/287)7.5% (22/292)
Hair loss

7.0% against 1.4%. It tracks how much weight is coming off rather than the drug itself, and the same rate showed up in the other trials of this drug.

7.0% (20/287)1.4% (4/292)
Serious adverse events of any kind

Close to the placebo rate, with no single problem affecting more than two people on the drug. One death occurred in each arm, neither judged related to treatment.

5.9% (17/287)4.8% (14/292)

Clinical significance

This is the strongest evidence that the drug and the behavioral work are additive rather than alternatives, and it is useful against both the argument that medication replaces effort and the argument that effort makes medication unnecessary. ⚠ The 18.4% is measured from randomization, after the lead-in loss, so it is not comparable to SURMOUNT-1's 20.9% measured from baseline. Adding the two together would overstate what anyone achieved.

Who sells tirzepatide, and for how much

This trial tested Tirzepatide. Across the 556 sellers on this register, 253 publish a standing monthly cash price for compounded tirzepatide, from $99 a month, with a median of $240.

⛔ None of those sellers was in this trial. A compounded preparation is not the product studied here: no agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and its concentration is set by whichever pharmacy filled it. The result above is the strongest evidence available for tirzepatide and it was generated on something else. Every seller, with its price record.

Frequently Asked Questions

References

  1. 1.Wadden TA, Chao AM, Machineni S, Kushner R, Ard J, Srivastava G, Halpern B, Zhang S, Chen J, Bunck MC, Ahmad NN, Forrester T. Tirzepatide after intensive lifestyle intervention in adults with overweight or obesity: the SURMOUNT-3 phase 3 trial. Nat Med. 2023. PMID: 37840095.
  2. 2.U.S. National Library of Medicine. A Study of Tirzepatide (LY3298176) In Participants After A Lifestyle Weight Loss Program (SURMOUNT-3) — Study Results. ClinicalTrials.gov, NCT04657016. 2024. https://clinicaltrials.gov/study/NCT04657016
  3. 3.Wilding JPH, Batterham RL, Calanna S, et al.; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021. PMID: 33567185.
  4. 4.Wadden TA, Bailey TS, Billings LK, Davies M, Frias JP, Koroleva A, Lingvay I, O'Neil PM, Rubino DM, Skovgaard D, Wallenstein SOR, Garvey WT; STEP 3 Investigators. Effect of Subcutaneous Semaglutide vs Placebo as an Adjunct to Intensive Behavioral Therapy on Body Weight in Adults With Overweight or Obesity: The STEP 3 Randomized Clinical Trial. JAMA. 2021. PMID: 33625476.
  5. 5.Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, Kiyosue A, Zhang S, Liu B, Bunck MC, Stefanski A; SURMOUNT-1 Investigators. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022. PMID: 35658024.

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