How do you confirm this is semaglutide and not a related analogue?

Two orthogonal methods on every lot. RP-HPLC gives area-percent purity against a qualified reference standard, and ESI LC-MS confirms the deconvoluted mass against the theoretical 4113.58 Da. A near-neighbour analogue will pass one of those and fail the other; both spectra are on the certificate.

Why does the vial contain more than the labelled peptide mass?

Lyophilised peptides are salts and carry residual water and counter-ion. The labelled figure is net peptide content, determined by amino acid analysis, not gross cake weight — so 10 mg on the label means 10 mg of peptide.

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GLP & MetabolicBest seller

GLP-1 (SG)

GLP-1 receptor agonist

A long-acting GLP-1 receptor agonist and the most-cited incretin analogue in current metabolic literature. Supplied as a lyophilised acetate salt with per-lot HPLC and LC-MS identity confirmation.

Current lot verified

CP-SEMAGLE3-2607A · tested Jul 14, 2026

99.35 %

HPLC purity

Read this lot’s certificate

About GLP-1 (SG)

Semaglutide is a structurally modified analogue of human glucagon-like peptide-1 in which substitution at position 8 blunts DPP-4 cleavage and a C18 diacid side chain drives reversible albumin binding. Together those two modifications extend the circulating half-life from minutes to roughly a week in published pharmacokinetic work, which is why it dominates the incretin literature. In receptor assays it behaves as a potent, selective GLP-1R agonist with downstream cAMP accumulation used as the standard readout.

For laboratory work the practical concern is analogue purity rather than potency. Semaglutide's sequence is close enough to several other incretin analogues that a single orthogonal test is not sufficient to establish identity, so every Certus lot is released on both reversed-phase HPLC area-percent and electrospray LC-MS mass confirmation, with the deconvoluted spectrum published on the lot certificate.

Published research areas

Incretin receptor signalling
Energy balance and satiety models
Glycaemic regulation in vitro
Gastric motility research

Specifications

CAS number: 910463-68-2
Molecular formula: C187H291N45O59
Molecular weight: 4113.58 g/mol
Release specification: ≥ 99.0 % by HPLC
Appearance: White to off-white lyophilised cake
Solubility: Soluble in bacteriostatic or sterile water; slightly alkaline buffers improve dissolution rate
Storage: Store lyophilised at -20 °C protected from light. Reconstituted material at 2–8 °C.
Format: lyophilized vial

Sequence

H-His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys(AEEA-AEEA-γGlu-C18 diacid)-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly-OH

Handling and reconstitution

Add diluent slowly down the vial wall and swirl — do not shake. Foaming shears long-chain acylated peptides and depresses recovered concentration.

Storage: Store lyophilised at -20 °C protected from light. Reconstituted material at 2–8 °C.

Full reconstitution and storage reference

Lot history

Every released lot of this compound, oldest kept on file. Average across 3 lots: 99.64 %.

Lot	Strength	Purity	Tested	Laboratory
CP-SEMAGLE3-2607A	5 mg	99.35 %	Jul 14, 2026	Aurum Bioanalytics	Certificate →
CP-SEMAGLE3-2604B	10 mg	99.82 %	Apr 23, 2026	Janoshik Analytical	Certificate →
CP-SEMAGLE3-2603C	15 mg	99.74 %	Mar 14, 2026	Aurum Bioanalytics	Certificate →

Selected literature

Listed for orientation. Citation is not endorsement of any outcome, and no claim is attached to any of these works.

Discovery of the once-weekly GLP-1 analogue semaglutide
Journal of Medicinal Chemistry
GLP-1 receptor agonists: mechanisms of action
Cell Metabolism

Questions about this compound

Two orthogonal methods on every lot. RP-HPLC gives area-percent purity against a qualified reference standard, and ESI LC-MS confirms the deconvoluted mass against the theoretical 4113.58 Da. A near-neighbour analogue will pass one of those and fail the other; both spectra are on the certificate.
Lyophilised peptides are salts and carry residual water and counter-ion. The labelled figure is net peptide content, determined by amino acid analysis, not gross cake weight — so 10 mg on the label means 10 mg of peptide.