The GLP receptor agonist class has moved from a single-receptor incretin story to a layered, multi-receptor design space in less than a decade. This is the Helixa in-house primer: no external links, no marketing detours — a clean orientation for researchers who need to pick the right reference peptide for a comparison study.
The three research references we stock
Helixa keeps three GLP-class references in the catalog, each engineered against a different receptor combination.
Semaglutide — the single-receptor GLP-1 agonist that anchors the class. Use it whenever your comparison needs the canonical GLP-1 arm. See the product page for lot COA and reconstitution notes: GLP-2 and GLP-3 pair naturally against it in receptor-isolation studies.
GLP-2 — a dual GLP-1 / GIP receptor agonist (the 'twincretin' architecture). Adds the GIP arm on top of GLP-1, which changes insulinotropic dynamics, lipolysis, and body-composition endpoints in preclinical models. Product page: Trizepitide (GLP-2).
GLP-3 — a triple GLP-1 / GIP / glucagon receptor agonist. Layers glucagon receptor activity on top of the twincretin base, which is why energy-expenditure and hepatic-lipid endpoints shift in the published phase-2 data. Product page: Retatrutide (GLP-3).
Why the receptor profile matters more than the molecule
From a mechanistic-research standpoint, the value of running these three side by side is that each additional receptor is a controlled variable. A well-designed animal or in-vitro protocol can attribute a change in glycemic control, body composition, or energy balance to the receptor combination being engaged — not to a specific brand name.
That framing is why we sell them as GLP-2 and GLP-3 rather than by their brand-name compound identifiers. The catalog is organized around the receptor pharmacology so your experimental notebook can be too.
Pharmacokinetics in plain terms
All three references are engineered for long plasma half-lives via fatty-acid sidechains that bind serum albumin, slowing renal clearance. In published human PK studies this translates to once-weekly dosing schedules. For in-vitro and rodent work, the practical consequence is that you can design steady-state exposure without daily handling.
Reconstitution and storage — the same for all three
Store lyophilized vials at -20 °C. Reconstitute with bacteriostatic water and keep the solution at 2–8 °C, using within roughly 30 days. Aliquot after reconstitution to avoid repeated freeze-thaw cycles, which are the single biggest source of drift between batches.
Every lot ships with an independent HPLC purity + mass-spec identity COA, plus endotoxin and sterility on the same lot. If your assay result drifts, the COA is the first place to rule the input in or out — see GLP-2 and GLP-3 lot pages for the raw certificates.
Choosing a reference for your study
A short decision guide for the most common comparison designs:
Isolating the GLP-1 arm — anchor on Semaglutide as the single-receptor control. Add Trizepitide (GLP-2) to introduce the GIP arm, and Retatrutide (GLP-3) to introduce glucagon on top.
Body-composition and energy-expenditure endpoints — GLP-3 is usually the informative arm because the glucagon receptor contribution is where the published data diverges most clearly from the twincretin baseline.
Gut-axis or insulinotropic dynamics — GLP-2 against Semaglutide isolates the GIP contribution cleanly without introducing the glucagon variable.
Related Helixa references
For metabolic and recovery panels alongside the GLP stack, researchers commonly co-order Tesamorelin (GHRH analog), MOTS-c (mitochondrial-derived peptide), and 5-Amino-1MQ (NNMT inhibitor). Each has its own primer in this journal.
In-vitro and laboratory use only
All Helixa references — including GLP-2, GLP-3, and every peptide in the catalog — are sold strictly for in-vitro research and laboratory use. Not for human or veterinary use, not a drug, not a supplement.