The answer, first. Tirzepatide is approved. Retatrutide is not — it is in phase 3, which means the pivotal evidence is still being generated. Retatrutide's published phase 2 weight-loss numbers are the strongest anyone has reported, and that is exactly why the comparison is misleading: phase 2 numbers are the ones that most often come down. If your question is which has a finished evidence record, the answer is tirzepatide, and it is not close.
Side by side
The same two axes this site applies to every compound, with nothing added for the comparison.
| Retatrutide | Tirzepatide | |
|---|---|---|
| Clinical evidence | phase 3 | approved |
| Community adoption | very high | very high |
| Category | weight loss | weight loss |
| Our summary | A triple agonist targeting GLP-1, GIP, and glucagon receptors. Investigational — phase 2 data is published, phase 3 is underway, and it is approved nowhere. We grade the evidence in a dedicated article. | A dual GLP-1 and GIP receptor agonist, FDA-approved as Mounjaro for type 2 diabetes and Zepbound for weight management. The benchmark the rest of the class is measured against. |
| Full file | Retatrutide → | Tirzepatide → |
What actually separates them
Three differences that hold up against the published record, rather than against marketing.
What neither can tell you
- What is in the vial. A comparison between molecules says nothing about the contents of a specific lot. Only a certificate of analysis does, and most cover fewer measures than buyers assume — start with how to read a COA.
- A dose. This site describes what published protocols used and never prescribes.
- Which is right for you. That is a clinical question about an individual, and nothing here is medical advice.
Questions we get
Is retatrutide better than tirzepatide?
On published phase 2 numbers retatrutide has reported the larger weight loss. On evidence quality tirzepatide is ahead, because its figures come from completed phase 3 trials and it holds an approval. Larger early numbers from an earlier trial stage are not the same as a better-established drug, and phase 2 results are the ones that most often fall when tested at scale.
Is retatrutide approved anywhere?
No. Retatrutide is in phase 3 development and is not approved in any jurisdiction. Anything sold as retatrutide on the research market is unapproved material, and no certificate can change that status.
Do the trial numbers apply to a research vial?
No. Published trial figures describe characterised material given at a controlled dose under supervision. They say nothing about the contents of a research vial, which is a separate question answered only by a certificate of analysis for that specific lot.