Trial review
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STEP-8: The approved product Against Liraglutide, Head to Head
How does weekly the drug compare with daily liraglutide for weight loss?
STEP-8 was a randomised, open-label, active-comparator, phase 3b funded by Novo Nordisk. Mean weight change approximately −15.8% on this medicine against approximately −6.4% on liraglutide and −1.9% on placebo. That figure belongs to the population, dose and 68 weeks shown below, and describes a group average rather than a prediction for any individual.
| Design | Randomised, open-label, active-comparator, phase 3b |
|---|---|
| Population | Adults with BMI 30 or above, or 27 or above with a comorbidity, without diabetes |
| Sample size | 338 |
| Intervention | The molecule 2.4 mg weekly |
| Comparator | Liraglutide 3.0 mg daily, and placebo |
| Duration | 68 weeks |
| Primary endpoint | Percentage change in body weight |
| Main result | Mean weight change approximately −15.8% on this GLP-1 against approximately −6.4% on liraglutide and −1.9% on placebo |
Show this figure as a table
| Step | Stage | What happens |
|---|---|---|
| 1 | Who was eligible | Adults with BMI 30 or above, or 27 or above with a comorbidity, without diabetes |
| 2 | What they received | Semaglutide 2.4 mg weekly |
| 3 | What it was compared against | Liraglutide 3.0 mg daily, and placebo |
| 4 | For how long | 68 weeks |
| 5 | What was measured first | Percentage change in body weight |
| 6 | What the group average was | Mean weight change approximately −15.8% on semaglutide against approximately −6.4% on liraglutide and −1.9% on placebo |
| 7 | What it does not tell you | A group average is not a prediction for any individual reader. |
Show this figure as a table
| Item | Weight change | Evidence |
|---|---|---|
| Semaglutide 2.4 mg | 16% | published, peer-reviewed |
| Liraglutide 3.0 mg | 6% | published, peer-reviewed |
| Placebo | 2% | published, peer-reviewed |
Show this figure as a table
| Item | Mean reduction | Evidence |
|---|---|---|
| Tirzepatide 15 mg (SURMOUNT-1) | 21% | Verified |
| Oral semaglutide 25 mg, adherent (OASIS 4) | 17% | Verified |
| Injectable semaglutide 2.4 mg (SURMOUNT-5) | 14% | Verified |
| Oral semaglutide 25 mg, treatment-policy (OASIS 4) | 14% | Verified |
| Orforglipron 17.2 mg (ATTAIN-1) | 12% | Reported |
| Liraglutide (SCALE) | 8% | Reported |
| Product | Starting self-pay price | Reported mean reduction | Trial |
|---|---|---|---|
| Zepbound (tirzepatide) injectable | $299/mo direct | about 20.9% at 15 mg | SURMOUNT-1, 72 weeks |
| Wegovy pill (oral semaglutide 25 mg) | $149/mo starting dose | 13.6–16.6% depending on estimand | OASIS 4, 64 weeks |
| Wegovy injectable (semaglutide 2.4 mg) | $349/mo maintenance | about 13.7% | SURMOUNT-5, 72 weeks |
| Foundayo (orforglipron) | $149/mo starting dose | about 11–12.4% at 17.2 mg | ATTAIN-1, 72 weeks |
Frequently asked questions
Does this apply to compounded versions?
No. The trial studied an FDA-approved product at studied doses.
Is this drug as effective as tirzepatide?
By mean reduction across separate trials, no. The efficacy ladder above sets out the figures with the trial that produced each one.
Related on this site
- Research hubResearch
- SURMOUNT-1 Tirzepatide Trial ExplainedResearch
- SURMOUNT-3 Tirzepatide Trial ExplainedResearch
- SURMOUNT-4: Weight Maintenance and Tirzepatide WithdrawalResearch
- The 100-point rubricCore & Trust
- Cost calculatorTools
- The underlying price recordsData
- Tirzepatide and Fatty Liver / MASHResearch
- Tirzepatide and Chronic Kidney DiseaseResearch
- Tirzepatide and Cardiovascular OutcomesResearch
Related coverage
GLP-1 Semaglutide Rx. “STEP-8: Semaglutide Against Liraglutide, Head to Head.” S.J Partners LLC, 2026-08-03. https://glp1semaglutiderx.com/research/step-8/
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