Semaglutide vs Tirzepatide vs Retatrutide
Compare the research, key figures and safety notes.
How they differ
Semaglutide activates GLP-1 receptors, tirzepatide activates GLP-1 and GIP receptors, and retatrutide adds glucagon-receptor activity. The cited studies used weekly subcutaneous formulations. Semaglutide and tirzepatide have licensed products; retatrutide remains investigational. This comparison draws on the cited 2023 phase-2 retatrutide study, not a complete review of its later development program. Amounts across different molecules are not measures of relative strength or interchangeable schedules.
Side by side
| Measure | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Category | Metabolic | Metabolic | Metabolic |
| Evidence | A · Human dose research | A · Human dose research | A · Human dose research |
| Route | Subcutaneous | Subcutaneous | Subcutaneous |
| Half-life | 168 h | 120 h | 144 h |
| Typical vial | 3 / 5 / 10 mg | 5 / 10 / 15 mg | 5 / 10 mg |
| Research amount | 0.25–2.4 mg | 2.5–15 mg | 0.5–12 mg |
| Common schedule | Once a week | Once a week | Once a week |
| Cycle / break | Titrated | Titrated | No validated self-directed course / — |
| Studied for | Metabolism and weight | Metabolism and weight | Metabolism and weight |
These amounts and schedules are figures discussed in research and community reports, shared for learning — not a recommendation and not medical advice. A step-by-step dosing schedule exists only where a human trial backs it; the evidence tier tells you which.
Decay curves, overlaid
Each line is scaled to that compound's own first dose, so the chart shows how each one builds up over time — not how the compounds' doses compare to one another, which these different molecules share no common unit for.
How they combine
Educational reference on commonly-discussed combinations, not medical advice. Combining compounds can change how each behaves — read this as a prompt to research, not a clearance.