Orforglipron vs Tirzepatide
The widest efficacy gap in the incretin class set against the widest convenience gap: a dual agonist injection versus a once-daily tablet — both now approved.
Orforglipron
~11% in ATTAIN-1; a scalable oral pill whose appeal is access, not peak efficacy. FDA-approved for weight management (Foundayo, 2026) — the type-2 diabetes indication is still under review.
Full Orforglipron evidence reviewTirzepatide
Zepbound / Mounjaro
Up to ~21% mean weight loss in SURMOUNT-1 — the most effective FDA-approved weight-management drug.
Full Tirzepatide evidence reviewSide by side
| Orforglipron | Tirzepatide | |
|---|---|---|
| Marketed for | Weight loss, type-2 diabetes | Weight loss, type-2 diabetes |
| Evidence grade | FDA-approved | FDA-approved |
| Family | GLP-1 / incretin | GLP-1 / incretin |
| Regulatory status | FDA-approved | FDA-approved |
| How it's obtained | Rx product | Rx product |
| Key human source | ATTAIN-1, NEJM 2025 | SURMOUNT-1, NEJM 2022 |
marks a row where the two differ. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
Our verdict
Tirzepatide is the more effective drug: SURMOUNT-1 reported mean reductions up to roughly 20.9%, and SURMOUNT-5 beat semaglutide in a genuine head-to-head. Orforglipron reported about 11% in ATTAIN-1, and since its 2026 FDA approval for weight management it is a real prescribing option rather than a pipeline entry. The two have never been compared directly, so the numbers sit in separate trials with different populations and durations. Read side by side, this is a straight trade between peak efficacy and a scalable pill — and both sides of that trade now exist as treatments.
Orforglipron fits if
You want the convenience of an ordinary daily tablet — no injection, no food or water timing — and roughly half the peak weight loss is an acceptable price.
Tirzepatide fits if
You want the largest average weight loss the approved options currently support and can accept a weekly injection.