Four compounds, four engineering strategies, four very different experimental fits. A structured comparison for Australian labs choosing a metabolic research peptide.
Native GLP-1 survives roughly two minutes in plasma before DPP-4 cleaves it. Every compound in this class exists to solve that stability problem, and the strategy each one uses determines how it behaves on the bench.
| Compound | Design strategy | Receptor targets | Published half-life |
|---|---|---|---|
| Semaglutide | C18 fatty-diacid albumin binding | GLP-1 | ~7 days |
| Tirzepatide | C20 acylation, dual-receptor sequence | GIP + GLP-1 | ~5 days |
| Retatrutide | Tri-agonist single chain | GIP + GLP-1 + glucagon | ~6 days |
| Cagrilintide | Long-acting amylin analogue | Amylin/calcitonin | ~7–8 days |
Choosing by research question, not popularity
- Isolating a single incretin pathway — a mono-agonist keeps the readout unambiguous
- Studying receptor crosstalk or co-activation — a dual or triple agonist reduces confounding from separate dosing schedules
- Modelling satiety signalling outside the incretin axis — an amylin analogue sits in a different mechanistic lane entirely
- Short-window in-vitro assays — half-life matters far less than purity and solubility consistency
Analytical difficulty scales with complexity
Longer, acylated sequences are harder to synthesise to a clean profile. That is exactly why Vitality Labs applies the same independent HPLC-MS release process to every compound in this class rather than testing the easy ones and assuming the rest.
Frequently asked
Which of these is 'best'?
There is no best — only best fit. The compound that matches your endpoint and timeline is the correct choice, and depth of published literature is a separate consideration from mechanistic suitability.
Do you stock all four in Australia?
Yes, all four are held in Australian stock at Vitality Labs and dispatched same business day once payment clears.
