Guide
Semaglutide vs Tirzepatide vs Retatrutide
These three are the most-discussed GLP-1 peptides, and they form a clear progression — single, dual, then triple receptor activity. More pathways generally means larger effects in research, but also a newer, shorter track record. Here's the honest, side-by-side breakdown to help you choose what fits your work.
The core difference: how many receptors
Semaglutide is a single agonist — it activates the GLP-1 receptor only. It's the most established of the three, with the deepest data and the gentlest, most predictable response. Tirzepatide is a dual agonist, adding GIP-receptor activity, which in research is associated with larger average effects than semaglutide. Retatrutide is a triple agonist — GLP-1, GIP, and glucagon — and that third pathway is why it draws so much attention as the next step in potency.
At a glance
| Semaglutide | Tirzepatide | Retatrutide | |
|---|---|---|---|
| Mechanism | GLP-1 | GLP-1 + GIP | GLP-1 + GIP + glucagon |
| Receptors | Single | Dual | Triple |
| Track record | Deepest | Strong | Newest |
| Typical research effect | Established baseline | Larger than sema | Largest in trials |
| Weekly dose range | Low (~0.25–2.4 mg) | Mid (~2.5–15 mg) | Mid (~2–12 mg) |
| Relative cost | Lowest | Mid | Highest |
Dosing cadence
All three are dosed weekly and titrated up slowly over weeks to manage tolerability — semaglutide uses the smallest milligram amounts, tirzepatide and retatrutide step up to higher weekly doses. Slow titration matters more as potency rises. Our dose-duration calculator walks the standard ladders for each, and the reconstitution calculator turns any vial into exact syringe units.
Cost
Cost tracks the progression: semaglutide is the most economical, tirzepatide sits in the middle, and retatrutide carries a premium as the newest, most potent compound. See live pricing on each product page — semaglutide, tirzepatide, retatrutide.
How to choose
If you want the most established option with the deepest data and the gentlest curve, semaglutide is the proven baseline. If you want stronger effects with a solid track record, tirzepatide is the workhorse most people land on. If you're specifically interested in the triple-agonist mechanism and the largest effect sizes seen in research, retatrutide is the frontier. Whichever you pick, insist on a verifiable COA — potency only matters if the batch is tested. Prefer a head-to-head? Read retatrutide vs tirzepatide.
For research use only. Not for human consumption. Nothing here is medical advice.