Semaglutide is the most extensively characterised GLP-1 receptor agonist in the research literature. This reference covers structure, receptor pharmacology, in-vitro binding data and handling for New Zealand laboratories.
The semaglutide peptide is a 31-residue synthetic GLP-1 receptor agonist and one of the most extensively characterised incretin peptides in modern research literature. This profile covers what a New Zealand laboratory needs to document semaglutide accurately for in-vitro work: structure, receptor pharmacology, published binding and cell-assay data, analytical specification and handling. Nothing on this page describes or supports human or animal use.
What is semaglutide?
Semaglutide is a synthetic peptide analog of native glucagon-like peptide-1 (GLP-1). Two structural modifications are of primary interest to researchers studying incretin-receptor stability: an α-aminoisobutyric acid (Aib) substitution at position 8 that blocks DPP-4 proteolytic cleavage in vitro, and a C18 fatty diacid spacer attached to Lys26 that enables reversible binding to serum albumin in plasma-protein-binding assays. Average mass is approximately 4113.6 Da.
Semaglutide identity and specifications
| Attribute | Value |
|---|---|
| Class | GLP-1 receptor mono-agonist (research reference) |
| Length | 31 amino acid residues |
| Molecular formula | C187H291N45O59 |
| Average mass | ~4113.6 Da |
| Backbone origin | Native GLP-1(7-37) analog |
| Key modifications | Aib8, C18 diacid at Lys26, Arg34 |
| Format supplied | Lyophilised powder, research use only |
| Storage (lyophilised) | -20 °C, protected from moisture |
Receptor pharmacology in vitro
Semaglutide is studied as a selective GLP-1 receptor ligand in cell-based assay systems. In transfected cell lines expressing the human GLP-1 receptor, binding elevates intracellular cAMP through Gs-protein coupling — the standard readout used in receptor-activation assays.
- Selective GLP-1R binding in radioligand and cAMP-accumulation assays — no meaningful cross-activity reported at GIP or glucagon receptors.
- Aib8 substitution confers resistance to DPP-4 proteolysis in plasma-stability assays.
- C18 fatty-acid conjugation is studied for its effect on albumin association and apparent in-vitro half-life in serum-stability models.
- Used as a reference ligand in comparative incretin-receptor pharmacology panels alongside other GLP-1R agonists.
Published in-vitro and structural literature
| Research focus | Assay type | Typical readout studied |
|---|---|---|
| GLP-1R binding affinity | Radioligand competition | IC50 / Ki |
| Receptor activation | cAMP accumulation (HEK293-GLP-1R) | EC50 |
| Plasma protein stability | Serum incubation + LC-MS | Apparent degradation half-life |
| DPP-4 resistance | Enzymatic digestion assay | Percent intact peptide over time |
Handling and storage reference
- Supplied as lyophilised powder for laboratory reconstitution into assay buffer only — not for injection or any human or animal application.
- Lyophilised material: stable at -20 °C for 24+ months when protected from moisture.
- Once reconstituted into aqueous buffer for bench use, store at 2–8 °C and use within the timeframe validated by your own assay protocol.
- Avoid repeated freeze–thaw cycles, which promote aggregation and compromise assay reproducibility.
Semaglutide vs tirzepatide vs retatrutide: receptor coverage
| Attribute | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Receptors studied | GLP-1 only | GIP + GLP-1 | GIP + GLP-1 + Glucagon |
| Backbone | GLP-1(7-37) analog | GIP-derived, GLP-1 cross-reactive | GIP-derived, triple cross-reactive |
| Albumin-binding strategy | C18 diacid, Lys26 | C20 diacid, Lys20 | Fatty-acid diacid linker |
Certificate of analysis expectations
- Batch identifier and synthesis date traceable to the lot record
- HPLC purity ≥98% (typically ≥99% for peptides under 30 residues)
- LC-MS confirmed monoisotopic or average mass within ±0.5 Da of theoretical
- Counterion identity and content (acetate or trifluoroacetate) reported
- Bacterial endotoxin and residual solvents per the analytical method
Sourcing research semaglutide in New Zealand
Kiwi Peps supplies research-grade semaglutide against the KP-99 Purity Standard (99%+ HPLC-MS), with every batch logged in The Batch Book. Orders placed and cleared by 2pm NZT ship the same working day via Bench-Ready Dispatch, tracked nationwide with NZ Post CourierPost. Strictly for in-vitro laboratory research — not for human or animal use.
Frequently asked questions
What is semaglutide used for in research?
Semaglutide is used as a reference ligand in GLP-1 receptor binding and activation assays, plasma-protein-binding studies and comparative incretin-receptor pharmacology panels — all in vitro.
What is the molecular weight of semaglutide?
Semaglutide has an average molecular mass of approximately 4113.6 Da across its 31-residue sequence.
How is semaglutide supplied by Kiwi Peps?
As lyophilised powder verified to the KP-99 Purity Standard, with a HPLC-MS certificate of analysis available through The Batch Book.
How should semaglutide be stored before use?
Keep the lyophilised powder at -20 °C, protected from moisture, until it is reconstituted into buffer for laboratory assay work.
Does semaglutide cross-react with other incretin receptors?
Published in-vitro binding data shows semaglutide is selective for the GLP-1 receptor, with no meaningful activity reported at GIP or glucagon receptors.
Is semaglutide approved for human use in New Zealand?
Kiwi Peps supplies semaglutide strictly as a research-use-only compound for in-vitro laboratory work. It is not sold, labelled or intended for human or animal administration.
