Semaglutide vs Tirzepatide: evidence, status and structure
A side-by-side look at Semaglutide and Tirzepatide, using the data on each VALREXA profile. Neither comparison is a recommendation.
Key differences
- Both sit at the same evidence level: Approved use.
- Both have the same U.S. status category: FDA-approved.
- Tirzepatide is about 1.2× heavier than Semaglutide (~4,813.5 vs ~4,113.6 Da).
| Semaglutide | Tirzepatide | |
| Research class | Metabolic Research | Metabolic Research |
| Human evidence | Approved use | Approved use |
| U.S. status | FDA-approved (Ozempic, Rybelsus, Wegovy) | FDA-approved (Mounjaro, Zepbound) |
| 2026 compounding decision | — | — |
| Amino acids | 31 (modified) | 39 (modified) |
| Molecular weight | ~4,113.6 Da | ~4,813.5 Da |
| Formula | C₁₈₇H₂₉₁N₄₅O₅₉ | C₂₂₅H₃₄₈N₄₈O₆₈ |
| Sequence | — | — |
| Research period | 2017 | 2022 |
| Safety summary | FDA-approved as Ozempic, Rybelsus and Wegovy (injection and tablet) for specific indications. Common side effects are gastrointestinal, and labels include a boxed warning about thyroid C-cell tumors seen in rodents. Products sold online as “research” semaglutide are not the approved drug. | FDA-approved as Mounjaro and Zepbound. Common side effects are gastrointestinal; labels include a boxed warning about thyroid C-cell tumors seen in rodents. |
How they differ
Semaglutide activates one receptor, the GLP-1 receptor. Tirzepatide activates two: the GIP and GLP-1 receptors. Both are approved once-weekly injections for type 2 diabetes and weight management, and semaglutide is also available as a tablet. In the SURMOUNT-5 head-to-head trial in adults with obesity, tirzepatide produced greater average weight loss than semaglutide. Side effects for both are mainly gastrointestinal.
What each one is
Semaglutide: GLP-1 receptor agonist peptide, modified to last about a week in the body. Molecular weight, sequence, research history, human evidence and regulatory status.
Tirzepatide: Dual GIP and GLP-1 receptor agonist peptide given once weekly. 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.