GLP-1 research peptides explained: the incretin science and the compounds

GLP-1 research peptides explained. The terms driving so much search interest — Mounjaro, Ozempic, semaglutide, tirzepatide — all trace back to one piece of physiology: the incretin receptor system. This guide is a plain, research-framed explainer of that science and of the research peptides Elite AU Peptides supplies for laboratory work. It is written cite-don’t-endorse: approved medicines are referenced only as the subject of published research, never endorsed, and never offered as products. Our compounds are supplied for in-vitro / laboratory research use only, with no medical, therapeutic, weight-loss, or human-use claim.

The incretin system in one paragraph

The incretin system refers to gut hormones — principally GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) — that act on their own class-B G-protein-coupled receptors as part of glucose-dependent insulin signalling and energy-homeostasis physiology. A third, related receptor, the glucagon receptor, sits in the same family. These three receptors — GLP-1, GIP and glucagon — are the targets that “GLP-1 research peptides” are studied against. Understanding them is the whole point of this space: the compounds differ mainly in how many of these receptors they engage.

The approved medicines (what we do not sell)

Semaglutide (marketed as Ozempic and Wegovy) is an approved single-receptor GLP-1 agonist; tirzepatide (marketed as Mounjaro and Zepbound) is an approved dual GIP/GLP-1 agonist. These are approved prescription medicines that Elite AU Peptides does not supply — they are referenced here only as the subject of published research. Tirzepatide’s dual-agonist profile is documented across the SURPASS clinical-trial programme (for example, Frías and colleagues, New England Journal of Medicine, 2021). We cite this literature as research findings; nothing here is a recommendation, an endorsement, or an offer to supply an approved medicine.

The research compounds we do supply

The research peptides in the GLP-class / metabolic category are studied against the same receptors. Retatrutide (LY3437943) is studied in published research as a single-peptide triple agonist of the GLP-1, GIP and glucagon receptors — its receptor pharmacology was reported by Coskun and colleagues (Cell Metabolism, 2022) and its first-in-human pharmacokinetics by Urva and colleagues (The Lancet, 2022). Tesamorelin is a stabilised GHRH-analogue studied in growth-hormone-axis research, and AOD-9604 is a synthetic growth-hormone-fragment studied in lipid-metabolism research. Each is supplied as a research-grade peptide for laboratory use only — not a medicine, and not a substitute for one.

How the compounds differ — receptor by receptor

The clearest way to hold the space in your head is by receptor count. Semaglutide engages one incretin receptor (GLP-1). Tirzepatide engages two (GLP-1 and GIP). Retatrutide is studied as engaging three (GLP-1, GIP and glucagon). That progression — one, two, three receptors — is the through-line of the published incretin-pharmacology literature, and it is the basis of the head-to-head research comparisons: the retatrutide vs tirzepatide and semaglutide vs retatrutide guides work through the mechanism in detail, and the Mounjaro vs Ozempic guide covers the two approved medicines factually.

Identity, purity and the COA moat

Every batch of the GLP-class research peptides supplied by Elite AU Peptides is independently HPLC-tested by Janoshik before it is listed. The measured purity is published on each product page and in the lab-reports library — a real batch number, the measured percentage, and an independently verifiable Janoshik report. For a research compound, verified identity and purity are the whole game; nothing is listed without a certificate on file. Browse the full GLP-class & metabolic research peptides category for the current catalogue.

Compliance and research-use framing

The research peptides referenced here are not TGA-approved, are not therapeutic goods, and are supplied strictly for in-vitro and laboratory research use only — not for human or animal consumption. Mounjaro, Ozempic, Wegovy, semaglutide and tirzepatide are approved medicines we do not supply, referenced only as published research. Elite AU Peptides makes no medical, therapeutic, weight-loss, or body-composition claim about any product, and makes no claim that any research peptide is a substitute for, or equivalent to, an approved medicine. Anything above is a research-reference summary of published literature, not medical advice; consult a qualified healthcare professional for any clinical question.