Evidence review
What 2025 trials showed about oral GLP-1 options — orforglipron (ATTAIN) and high-dose oral semaglutide (OASIS-4) — and what they mean for patients.
Published June 1, 2026 · GLP1 One Telehealth Editorial Team
Recent 2025 trials show oral GLP-1s can produce meaningful weight loss: orforglipron about 11–12% (ATTAIN-1, NEJM 2025) and high-dose oral semaglutide about 13.6% (OASIS-4, 2025). These are promising but were not all FDA-approved at the time of writing.
Educational use only. This article is for educational purposes only and does not provide medical advice. Compounded semaglutide and compounded tirzepatide are not FDA-approved finished drug products and should only be prescribed when clinically appropriate by a licensed healthcare provider.
Mean weight loss in pivotal GLP-1 trials
| Medication | Trial (year) | Mean weight loss |
|---|---|---|
| Tirzepatide 15 mg | SURMOUNT-1 (2022) | 20.9% |
| Tirzepatide | SURMOUNT-5 (2025) | 20.2% |
| Semaglutide 2.4 mg | STEP 1 (2021) | 14.9% |
| Semaglutide 2.4 mg | SURMOUNT-5 (2025) | 13.7% |
| Oral semaglutide 25 mg | OASIS-4 (2025) | 13.6% |
| Oral orforglipron 36 mg | ATTAIN-1 (2025) | 12.4% |
Compounded versions are not the FDA-approved products studied in these trials.
ATTAIN-1 and ATTAIN-2 evaluated orforglipron in obesity and type 2 diabetes; OASIS-4 studied oral semaglutide 25 mg. Oral options may improve access for patients who prefer pills over injections, with class-typical gastrointestinal side effects.
Investigational or newly studied medicines are not the same as compounded products sold online today. Approval and availability change; rely on a licensed clinician and verify what a program actually prescribes.
2025 trials show meaningful loss (about 11–14%); injectable tirzepatide produced more in head-to-head data.
Approval and availability evolve; never use research-labeled products, and compounded products are not FDA-approved.