Nova Biolabs stocks the main peptides used in weight-management research — Tirzepatide, Retatrutide, Semaglutide and Cagrilintide — domestically in the UK, with same or next-day dispatch in discreet packaging. Here's how they differ and how to pick the right one for your research.
Most of what's searched for as "weight loss peptides" falls into two families: incretin receptor agonists (GLP-1, GIP and glucagon-based compounds) and amylin receptor agonists. They work on different pathways, and the incretin family in particular has expanded quickly — each new compound adding another receptor to the mechanism.
| Compound | Receptors targeted | From |
|---|---|---|
| Semaglutide | GLP-1 (single) | £20 |
| Tirzepatide | GLP-1 + GIP (dual) | £30 |
| Retatrutide | GLP-1 + GIP + Glucagon (triple) | £35 |
| Cagrilintide | Amylin (long-acting) | £45 |
Semaglutide targets the GLP-1 receptor only, making it the reference compound most other incretin research is benchmarked against. It's the longest-studied of the four and the starting point for understanding GLP-1 receptor pharmacology before layering in additional receptor activity.
Tirzepatide adds GIP receptor agonism to GLP-1, engaging two incretin pathways simultaneously. This dual mechanism is of particular research interest for studying how the two receptors interact rather than act independently. Full Tirzepatide guide →
Retatrutide goes a step further, adding glucagon receptor agonism on top of GLP-1 and GIP. The glucagon component is what distinguishes it — it engages hepatic glucose output and energy expenditure pathways that dual agonists don't directly touch. Full Retatrutide guide →
Cagrilintide isn't an incretin analogue at all — it's a long-acting amylin receptor agonist. Amylin is co-secreted with insulin and acts on satiety signalling through a separate pathway, which is why Cagrilintide is often studied alongside a GLP-1 compound rather than as a substitute for one. View Cagrilintide 10mg →
There's no single "strongest" compound here — each targets a different combination of receptors, and which one is right for a given research protocol depends on which pathway you're actually studying, not just how many receptors a compound engages.
All four are supplied lyophilised and require reconstitution with bacteriostatic water before use. Store at 2–8°C away from light, use the peptide dosing calculator for exact measurements, and use reconstituted material within 28 days. See the full reconstitution guide for detail.
All Nova Biolabs peptides are research grade, held in UK stock for same or next-day dispatch.
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