Incretin-related and amylin peptides
Semaglutide
Semaglutide is a synthetic 31-residue analogue of human glucagon-like peptide-1 (GLP-1) that carries a fatty diacid side chain on lysine 26 and an α-aminoisobutyric acid (Aib) residue at position 8.
- TypePeptide
- FormulaC187H291N45O59
- Average mass4113.58 g/mol
- CAS910463-68-2
- Vesta listings7
Reference page for laboratory use · updated 2026-10-30
Overview
Semaglutide at a glance
GLP-1 is an incretin hormone released from the gut that acts on the GLP-1 receptor. Semaglutide was designed by Novo Nordisk as a long-acting analogue, and the discovery work is described in the medicinal chemistry literature (J Med Chem, 2015).
In research settings it is used as a GLP-1 receptor reference agonist in receptor pharmacology, signalling and animal-model studies. Vesta supplies it as a research material only; it is not the pharmaceutical product that is sold under similar names.
Structure
The backbone follows GLP-1(7-37) with Aib at position 8 and arginine at position 34. The side chain on Lys26 is a C18 fatty diacid joined through a γ-glutamic acid and polyethylene-glycol-type spacer, which promotes binding to serum albumin. These non-standard parts mean the molecule cannot be described by a plain amino acid sequence alone.
Identity
Identity data
| Name | Semaglutide |
|---|---|
| Also written as | NN9535, Semaglutide acylated GLP-1 analogue |
| Type | Peptide |
| Research area | Incretin-related and amylin peptides |
| Molecular formula | C187H291N45O59 |
| Monoisotopic mass | 4111.1154 Da |
| Average molecular weight | 4113.58 g/mol |
| CAS number | 910463-68-2 |
| PubChem record | CID 56843331 |
The formula comes from the PubChem record; monoisotopic mass is calculated from the formula and the average mass uses standard atomic weights. Reference data retrieved on 2026-10-30. Compare these values with the batch certificate of analysis, using the compound identity file template.
Expected values
Mass spectrometry reference
Ions calculated from the monoisotopic mass 4111.1154 Da. Use them to check an LC-MS result; for larger peptides the instrument usually reports a deconvoluted mass close to 4113.6 Da instead.
| Ion | m/z |
|---|---|
| [M+3H]3+ | 1371.3791 |
| [M+4H]4+ | 1028.7861 |
| [M+5H]5+ | 823.2304 |
| [M+6H]6+ | 686.1932 |
For molecules of this size the tallest isotope peak is one to two mass units above the monoisotopic peak. Read the guide to average and monoisotopic mass for how these values are calculated.
Quality
Analytical notes for batch documents
- Because the lipid side chain and Aib are not standard residues, a useful COA reports the measured intact mass, not only a sequence-based expectation.
- Large, lipidated peptides usually show a charge envelope (for example 3+ to 6+) in electrospray mass spectrometry; the intact mass is obtained by deconvolution.
- The molecular weight of a vial of powder includes counter-ions and water; the share of the powder that is peptide is the net peptide content.
Terms used on this page: Lipidation, Mass spectrometry, Deconvolution.
Vesta listings
Semaglutide formats and prices
| Product | Per vial | SKU | Price per kit | Price per vial |
|---|---|---|---|---|
| Semaglutide | 5 mg | SM5 | $29.85 | $2.99 |
| Semaglutide | 10 mg | SM10 | $42.91 | $4.29 |
| Semaglutide | 15 mg | SM15 | $61.57 | $6.16 |
| Semaglutide | 20 mg | SM20 | $70.90 | $7.09 |
| Semaglutide | 30 mg | SM30 | $104.48 | $10.45 |
| Semaglutide | 40 mg | SM40 | $134.33 | $13.43 |
| Semaglutide | 50 mg | SM50 | $156.72 | $15.67 |
Prices are per kit of 10 vials in US dollars. Shipping is paid by the customer and is shown in the cart. Volume savings of 5 %, 8 % and 10 % apply from $350.00, $600.00 and $1,000.00. See the full price list.
Published literature
Selected scientific literature
Bibliographic details were read from PubMed on 2026-10-30. The papers are listed for scientific reference; Vesta makes no claim about the use of its research materials in people or animals.
- Discovery of the Once-Weekly Glucagon-Like Peptide-1 (GLP-1) Analogue SemaglutideLau J, Bloch P, Schäffer L et al. · J Med Chem · 2015 · PMID 26308095
- The Discovery and Development of Liraglutide and SemaglutideKnudsen LB, Lau J · Front Endocrinol (Lausanne) · 2019 · PMID 31031702
- Semaglutide lowers body weight in rodents via distributed neural pathwaysGabery S, Salinas CG, Paulsen SJ et al. · JCI Insight · 2020 · PMID 32213703
Questions
Frequently asked questions
What is Semaglutide?
Semaglutide is a synthetic 31-residue analogue of human glucagon-like peptide-1 (GLP-1) that carries a fatty diacid side chain on lysine 26 and an α-aminoisobutyric acid (Aib) residue at position 8.
What is the molecular weight of Semaglutide?
Semaglutide has the formula C187H291N45O59, an average molecular weight of 4113.58 g/mol and a monoisotopic mass of 4111.1154 Da. A salt form, a different counter-ion or a metal complex changes the molecular weight printed on a certificate of analysis, so compare like with like.
How can I check the identity of a batch of Semaglutide?
Compare the intact mass measured by LC-MS with the expected values on this page, for example [M+4H]4+ at m/z 1028.7861. Confirm that one main HPLC peak carries that mass and that the batch code on the report matches the vial. The guides on mass spectrometry and on certificates of analysis explain each step.
Which Semaglutide products does Vesta list?
Vesta lists 7 products for Semaglutide: 5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 50 mg per vial in kits of 10 vials. Prices are shown per kit in US dollars, and shipping is paid by the customer.