VIP for Sale | COA-Verified Research Peptide

What VIP Is

VIP, or vasoactive intestinal peptide, is a 28 residue neuropeptide first isolated from porcine intestinal tissue and later identified across neural, gastrointestinal, and immune tissue in mammalian model systems. Structurally it belongs to the secretin and glucagon superfamily, and the research literature describes its association with the class B G protein coupled receptors VPAC1 and VPAC2. Published work referencing VIP spans neuroendocrine signaling, circadian rhythm research in suprachiasmatic nucleus model systems, smooth muscle and vasodilation studies, and immune signaling investigations in cell culture.

That breadth is exactly why sourcing matters. A compound that appears across several unrelated model systems tends to be ordered by laboratories with very different assay sensitivities, and a batch that is adequate for one readout may be quietly inadequate for another. The question this page addresses is narrow and practical: how a researcher confirms the identity and purity of a VIP batch before it enters an experiment.

Why a 28 Residue Peptide Is a Harder Sourcing Problem

Longer sequences are meaningfully more difficult to synthesize cleanly than short ones, and VIP sits well past the length where solid phase synthesis errors start accumulating in measurable amounts. Three failure modes are worth knowing by name when reading a supplier documentation package:

Deletion and truncation sequences. Each coupling step in a 28 residue synthesis is slightly less than perfect. Incomplete couplings produce sequences missing one or more internal residues, and these byproducts sit close enough in mass and retention time to the target that they only resolve on a properly run HPLC gradient.
Methionine oxidation. The VIP sequence contains a methionine residue, and methionine is among the most oxidation prone amino acids. An oxidized batch carries a mass shift of roughly 16 Da, which is readily visible on mass spectrometry but invisible to the eye, and invisible on a COA that reports only a purity number with no supporting data.
Asparagine and glutamine deamidation. VIP carries several amide side chains that can deamidate over time, particularly under poor storage or shipping conditions, producing charge variants of the intended molecule.

None of these are exotic. They are the ordinary consequences of synthesizing and shipping a mid length peptide, which is precisely why the documentation attached to a batch carries more weight here than it would on a tripeptide.

What a Real Certificate of Analysis Should Include

A Certificate of Analysis (COA) ties one specific batch to its test results. For a peptide of this length, confirm the COA includes:

Batch or lot number matching the product actually received
Third-party testing, not only in-house results
HPLC purity percentage with the chromatogram attached, so adjacent peaks stay visible rather than summarized away
Mass spectrometry identity confirmation showing the observed mass against the theoretical mass
Test date and the name of the testing laboratory
Peptide content or net peptide value where reported, since gross vial weight includes counterions and residual water

A COA that is generic, undated, or not tied to a specific batch number is not verification. It is marketing collateral.

Nordiscience Sourcing Standards

Nordiscience sources VIP under GMP-following manufacturing protocols and independently verifies each batch through third-party laboratory testing. A Certificate of Analysis is available on request for every batch sold, including HPLC purity data and mass spectrometry identity confirmation, so a batch can be qualified against the intended assay before it reaches the bench.

Built for Researchers Who Order Directly

Beyond the compound itself, Nordiscience is built around the procurement friction that slows laboratory ordering: standard credit card, Apple Pay, and Google Pay checkout with no crypto-only paywall, fast US shipping, and a support team reachable by email or WhatsApp for sourcing and documentation questions.

Access VIP Documentation

Request a Certificate of Analysis for any current batch, or send sourcing questions, to info@nordiscience.com or via WhatsApp (Monday through Friday, 9 AM to 5 PM Mountain Time).

For Research Use Only. Not for human consumption. Not for veterinary use. Not for diagnostic use. All products listed on this site are intended for laboratory research and identification purposes only. Products have not been evaluated by the FDA.

Age Verification Required

Research Use Only Notice

VIP for Sale | Research-Grade Peptide, COA-Verified | Nordiscience