Trial review
ATTAIN-1: Orforglipron for Weight Management, Explained
Orforglipron for chronic weight management
Direct answer
ATTAIN-1 was a phase 3, randomised, double-blind, placebo-controlled funded by Eli Lilly and Company. Approximately 11% to 12.4% mean weight reduction at the highest dose over 72 weeks. Lilly states 12.4% at the highest dose; secondary coverage cites approximately 11%. That figure belongs to the population, dose and 72 weeks shown below, and describes a group average rather than a prediction for any individual.
ATTAIN-1 at a glanceProvider-reported
| Design | Phase 3, randomised, double-blind, placebo-controlled |
|---|---|
| Population | Adults with obesity, or overweight with weight-related comorbidities. Over 1,600 randomised across the US, Argentina, Australia, Brazil, China, Czechia, Germany, Greece, India, South Korea and Puerto Rico |
| Sample size | Over 1,600 randomised |
| Intervention | Orforglipron, once-daily oral non-peptide GLP-1 receptor agonist |
| Comparator | Placebo |
| Duration | 72 weeks |
| Primary endpoint | Mean percentage change in body weight from baseline at 72 weeks |
| Main result | Approximately 11% to 12.4% mean weight reduction at the highest dose over 72 weeks. Lilly states 12.4% at the highest dose; secondary coverage cites approximately 11% |
find this trial on ClinicalTrials.govLast source check: 2026-07-24
Show this figure as a table
| Step | Stage | What happens |
|---|---|---|
| 1 | Who was eligible | Adults with obesity, or overweight with weight-related comorbidities. Over 1,600 randomised across the US, Argentina, Australia, Brazil, China, Czechia, Germany, Greece, India, South Korea and Puerto Rico |
| 2 | What they received | Orforglipron, once-daily oral non-peptide GLP-1 receptor agonist |
| 3 | What it was compared against | Placebo |
| 4 | For how long | 72 weeks |
| 5 | What was measured first | Mean percentage change in body weight from baseline at 72 weeks |
| 6 | What the group average was | Approximately 11% to 12.4% mean weight reduction at the highest dose over 72 weeks. Lilly states 12.4% at the highest dose; secondary coverage cites approximately 11% |
| 7 | What it does not tell you | A group average is not a prediction for any individual reader. |
Strip any step and the result stops meaning what the trial found.
Show this figure as a table
| Item | Weight change | Evidence |
|---|---|---|
| Orforglipron 17.2 mg | 12% | Provider-reported |
Group means under trial conditions with lifestyle intervention. Not a prediction for any individual reader.
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% | Provider-reported |
| Liraglutide (SCALE) | 8% | Provider-reported |
These come from different trials and are not a head-to-head comparison. Durations differ (64 to 72 weeks) and estimands differ. Only SURMOUNT-5 compared two of these drugs directly.
| 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 |
Both $149 products are the least effective approved options in this table. That does not make them bad choices — it makes a price comparison that omits efficacy an incomplete one.
Before publish — primary-source capture
- Capture the NCT identifier, the peer-reviewed publication, the estimand behind each reported figure, and discontinuation rates. Do not chart a single efficacy number until the estimand is established.
Questions readers actually ask
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
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- SURMOUNT-4: Weight Maintenance and Tirzepatide WithdrawalResearch
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- The underlying price recordsData
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Cite this pageCC BY 4.0
GLP-1 Tirzepatide Review. “ATTAIN-1: Orforglipron for Weight Management, Explained.” S.J Partners LLC, 2026-07-24. https://glp1tirzepatidereview.com/research/attain-1/
When quoting a figure, include the capture date shown beside it rather than the date you read this page. A price without its capture date is not a usable citation.