Tirzepatide vs Retatrutide: evidence, status and structure
A side-by-side look at Tirzepatide and Retatrutide, using the data on each VALREXA profile. Neither comparison is a recommendation.
Key differences
- Tirzepatide has stronger human evidence (Approved use) than Retatrutide (Controlled trials).
- Their U.S. status differs: Tirzepatide falls under FDA-approved (FDA-approved (Mounjaro, Zepbound)); Retatrutide falls under Investigational (Investigational (Phase 3)).
| Tirzepatide | Retatrutide | |
| Research class | Metabolic Research | Metabolic Research |
| Human evidence | Approved use | Controlled trials |
| U.S. status | FDA-approved (Mounjaro, Zepbound) | Investigational (Phase 3) |
| 2026 compounding decision | — | — |
| Amino acids | 39 (modified) | 39 (modified) |
| Molecular weight | ~4,813.5 Da | ~4,731.4 Da |
| Formula | C₂₂₅H₃₄₈N₄₈O₆₈ | C₂₂₁H₃₄₂N₄₆O₆₈ |
| Sequence | — | — |
| Research period | 2022 | 2020s |
| Safety summary | FDA-approved as Mounjaro and Zepbound. Common side effects are gastrointestinal; labels include a boxed warning about thyroid C-cell tumors seen in rodents. | Investigational and not FDA-approved. Products sold online as “retatrutide” are unregulated and are not the investigational drug. |
How they differ
Tirzepatide is an approved dual agonist of the GIP and GLP-1 receptors. Retatrutide adds a third target, the glucagon receptor, making it a "triple agonist." Retatrutide is still investigational: it is in Phase 3 trials and is not FDA-approved, so products sold online under that name are unregulated.
What each one is
Tirzepatide: Dual GIP and GLP-1 receptor agonist peptide given once weekly. Molecular weight, sequence, research history, human evidence and regulatory status.
Retatrutide: Investigational triple agonist of the GIP, GLP-1 and glucagon receptors. Molecular weight, sequence, research history, human evidence and regulatory status.
Educational reference only. Nothing here is medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error.