Semaglutide
Molecular Research Profile ยท Target purity > 99.0% ยท Half-life ~7 days
Single-agonist GLP-1 receptor agonist. The foundational compound in the incretin mimetic class, with extensive clinical characterization and well-established purity benchmarks in research settings.
Semaglutide Molecular Formula, Structure & Chemical Identity
Reference identifiers researchers use to verify that a vial matches what a vendor claims to have shipped. Cross-check these values against any Certificate of Analysis before accepting a purity figure.
| Molecular Formula | C187H291N45O59 |
|---|---|
| Molecular Weight | 4113.6 g/mol |
| CAS Number | 910463-68-2 |
| Amino Acid Count | 31 |
| Amino Acid Sequence | His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly |
| Also Known As | NN9535, Ozempic, Wegovy, Rybelsus |
| PubChem CID | 56843331 ↗ |
Identifiers verified against the NIH PubChem compound database. Molecular weights independently recalculated from the molecular formula using IUPAC 2021 standard atomic weights.
How to Read a Semaglutide Certificate of Analysis
A COA is only meaningful if the identifiers on it match the compound you ordered. Four checks, in order.
- 1. Identity โ does the formula match?The COA header should state C187H291N45O59 and a molecular weight near 4113.6 g/mol, with CAS 910463-68-2. A mismatch means you are not looking at a COA for this compound.
- 2. Purity โ HPLC chromatogram, not just a numberA printed “> 99.0%” with no chromatogram is a marketing claim. Demand the actual HPLC trace: a single dominant peak, labelled retention time, and an integration table. Shoulders or unlabelled side peaks are unreported impurities.
- 3. Mass confirmation โ does MS agree with the formula?Mass spectrometry should report an observed mass consistent with the expected 4113.6 g/mol. Peptides are frequently reported as multiply charged ions, so the raw m/z value will be lower than the neutral mass. An unexplained offset is a red flag.
- 4. Provenance โ who signed it, and for which batch?A valid COA names the testing laboratory, carries a batch or lot number that matches your vial label, and is dated. A vendor-produced PDF with no lab identity and no batch number is not third-party evidence.
Full methodology in ourguide to the 5 COA red flags researchers miss, or verify the reconstitution math with thepeptide reconstitution calculator.
Mechanism of Action
Semaglutide is a GLP-1 receptor agonist with 94% sequence homology to native human GLP-1, engineered with two key modifications: an amino acid substitution at position 8 (ฮฑ-aminoisobutyric acid for alanine) conferring DPP-IV resistance, and a C18 fatty diacid chain at lysine-26 promoting albumin binding for extended half-life (~7 days). These modifications extend the plasma half-life from ~2 minutes (native GLP-1) to approximately 165 hours.
At the GLP-1 receptor, semaglutide activates cAMP-PKA signaling in pancreatic ฮฒ-cells (glucose-dependent insulin secretion), suppresses glucagon release from ฮฑ-cells, and reduces hepatic gluconeogenesis. In the central nervous system, it activates GLP-1 receptors in the arcuate nucleus and area postrema, producing satiety signaling and reduced food intake. Gastric emptying is dose-dependently delayed, contributing to postprandial glycemic control.
Compared to tirzepatide (dual GIP/GLP-1) and retatrutide (triple GIP/GLP-1/GCG), semaglutide is a purer research tool for isolating GLP-1-specific effects. Its well-characterized binding kinetics and extensive clinical data make it the standard reference compound for GLP-1 receptor agonism studies.
Research History & Context
Semaglutide was developed by Novo Nordisk, building on the liraglutide platform. Phase 3 SUSTAIN trials (2016โ2018) for type-2 diabetes and STEP trials (2018โ2021) for obesity demonstrated mean body-weight reductions of approximately 15% at 68 weeks. Clinical authorization was granted in 2017 (Ozempic, T2D) and 2021 (Wegovy, obesity).
As a research peptide, semaglutide is among the most analytically characterized GLP-1-family compounds available from independent suppliers. Its widespread clinical use means HPLC reference standards are readily available, and purity expectations (>99.0%) are well-calibrated against pharmaceutical-grade benchmarks.
Storage & Handling
Store lyophilized semaglutide at -20ยฐC in a dry, dark environment. Stability exceeds 24 months. The fatty-acid moiety makes semaglutide more hydrophobic than tirzepatide; ensure complete dissolution during reconstitution (swirl for 60โ90 seconds rather than agitate).
After reconstitution with bacteriostatic water, semaglutide should be refrigerated at 2โ8ยฐC and used within 28 days. The peptide forms multimers (primarily hexamers) in solution at the zinc-containing concentrations found in pharmaceutical formulations; research-grade material typically forms dimers and tetramers at standard reconstitution concentrations, which does not affect receptor binding.
Reconstitution & Research Dosing
For Semaglutide, the standard laboratory reconstitution is 2.0 ml BAC water for 5mg vial. A typical research study window uses 0.25 - 1.0 mg / week (titration protocol).
For a 5mg semaglutide research vial, add 2.0 ml BAC water (2.5 mg/ml). For micro-dosing protocols, add 5.0 ml BAC water (1.0 mg/ml) to facilitate precise low-volume dosing. The standard weekly research protocol makes semaglutide one of the more convenient GLP-1 peptides โ a single reconstituted vial typically covers 4โ8 weeks of research.
Use the Reconstitution Calculator for exact syringe units →Audited Vendors Stocking Semaglutide
Each review checks whether the testing lab is named and whether COAs can be verified at the issuing lab.
Related Semaglutide Research
Semaglutide FAQ
QWhat is the molecular formula of Semaglutide?
Semaglutide has the molecular formula C187H291N45O59 and a molecular weight of approximately 4113.6 g/mol. Its CAS registry number is 910463-68-2. It is a 31-residue peptide with the sequence His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly.
QHow do you verify a Semaglutide Certificate of Analysis?
Check four things in order. First, identity: the COA must state C187H291N45O59 and CAS 910463-68-2. Second, purity: require the actual HPLC chromatogram with retention time and integration table, not just a printed percentage. Third, mass confirmation: the mass spectrometry result must agree with the expected molecular weight of 4113.6 g/mol, allowing for multiply charged ions. Fourth, provenance: the COA must name the testing laboratory and carry a batch number matching your vial label.
QWhat purity should Semaglutide be?
Research-grade Semaglutide should meet a purity target of > 99.0%, confirmed by third-party HPLC analysis rather than a vendor self-declaration. A purity claim without an accompanying chromatogram carries no evidential weight.
QWhat is the half-life of Semaglutide?
The reported half-life of Semaglutide is ~7 days. Half-life figures come from published research models and vary with species, route and formulation, so treat them as a reference range rather than a fixed value.
QHow much bacteriostatic water do you add to Semaglutide?
The standard reconstitution for Semaglutide is 2.0 ml BAC water for 5mg vial. For a 5mg semaglutide research vial, add 2.0 ml BAC water (2.5 mg/ml). For micro-dosing protocols, add 5.0 ml BAC water (1.0 mg/ml) to facilitate precise low-volume dosing. The standard weekly research protocol makes semaglutide one of the more convenient GLP-1 peptides โ a single reconstituted vial typically covers 4โ8 weeks of research.
Explore Related Research Compounds
Research Use Only (RUO): Semaglutide is discussed strictly as an in-vitro laboratory research compound. Nothing on this page constitutes human or clinical administration guidance. Always verify purity through independent third-party HPLC/MS analysis before use.