Orforglipron vs Tirzepatide
The widest efficacy gap in the incretin class set against the widest convenience gap: an approved dual agonist injection versus an investigational once-daily tablet.
Orforglipron
~11% in ATTAIN-1; a scalable oral pill whose appeal is access, not peak efficacy. Investigational.
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 | Clinical data | FDA-approved |
| Family | GLP-1 / incretin | GLP-1 / incretin |
| Regulatory status | Investigational | FDA-approved |
| How it's obtained | Research-only | 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 and the only one of the two that can be prescribed; 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 remains investigational. 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 trade between peak efficacy and a scalable pill, and only one side of that trade currently exists as a treatment.
Orforglipron fits if
You care whether GLP-1 therapy can scale down to an ordinary daily tablet, and you are reading the pipeline rather than choosing a prescription.
Tirzepatide fits if
You want the largest average weight loss the approved options currently support and can accept a weekly injection.