GLP-1 metabolic peptides: Retatrutide & Tirzepatide

The GLP-1 class has become the most talked-about area of metabolic research. This is an educational overview of the compounds and the science that studies them — laboratory reference only. It is not medical, dosing, or clinical advice, and nothing here is for human or animal use.

The incretin system, briefly

"Incretin" hormones such as GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) are gut-derived signals studied for their role in glucose handling and energy balance. Research peptides in this class are receptor agonists — molecules that engage one or more of these receptors in the models being studied.

Tirzepatide — dual agonist

Tirzepatide is a GIP/GLP-1 dual receptor agonist — it engages two incretin receptors at once. In the catalog it is a Metabolic-class peptide with a long research half-life (on the order of days). Our 20 mg vial is the best value per-mg in the range.

Retatrutide — triple agonist

Retatrutide is newer still: a triple GLP-1/GIP/glucagon receptor agonist. Adding glucagon-receptor activity is what makes it the frontier of this research area. It is likewise long-acting in the systems studied and sits alongside Tirzepatide in the Metabolic class.

How they're studied

Work in this class centres on glucose regulation, insulin sensitivity, appetite signalling and energy balance in cell and animal models. Because these are potent signalling molecules, purity and correct identity are especially important for reproducible bench results — which is where the certificate of analysis comes in.

Handling and verification

These peptides are reconstituted with bacteriostatic water and kept cold, like the rest of the catalog (see the reconstitution and storage guides). Before buying any metabolic peptide, check the COA: HPLC purity with a chromatogram, mass-spec identity, and a matching lot number.