Retatrutide vs tirzepatide
What the research says about each, side by side. Every row comes from the studies and drug labels in the last row. More on each: Retatrutide and Tirzepatide.
| Retatrutide | Tirzepatide | |
|---|---|---|
| Category | GLP-1 and metabolic | GLP-1 and metabolic |
| Evidence | Ongoing clinical research | Extensive clinical research |
| FDA status | Investigational. Not FDA-approved. | FDA-approved as Mounjaro (2022, type 2 diabetes) and Zepbound (2023, weight management; 2024, sleep apnea with obesity). Compounded copies aren't FDA-approved. |
| How it works | The GLP-1 and GIP parts curb appetite and help insulin release. The glucagon part raises the body's energy use and pushes the liver to burn more fat. | The GLP-1 part lowers appetite, slows the stomach and helps insulin release. GIP is a second gut hormone that also boosts insulin after meals and seems to add to the effect on appetite and fat tissue. Hitting both receptors with one molecule gives more weight loss than GLP-1 alone in head-to-head trials. |
| Half-life | About 6 days in early human studies, which supports weekly shots. | About 5 days. Levels peak 8–72 hours after a shot and reach a steady level after about 4 weeks of weekly shots. |
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