What the label states, the lot delivers — net peptide mass, not gross powder weight, purity reported as measured rather than rounded up, and a Certificate of Analysis for every lot.
Net peptide mass, not powder weight; purity as measured, not rounded up; a COA per lot.
Net peptide + purity not rounded up. COA per lot.
FDA PCAC reviews 7 peptides for the 503A bulks list (BPC-157, KPV, TB-500, MOTs-C, Emideltide, Semax, Epitalon). Read our compounder's decision tree. Read our briefing →
FDA PCAC reviews 7 peptides for the 503A bulks list in July. Read →
FDA PCAC: 7 peptides under review. Read →
28-residue vasoactive / immune neuropeptide
Overview
VIP (Vasoactive Intestinal Peptide) is a 28-amino-acid endogenous neuropeptide widely distributed across the central and peripheral nervous systems, the gastrointestinal tract, and immune cells. It has potent anti-inflammatory, immunomodulatory, neuroprotective, and vasodilatory effects, acting through VPAC1/VPAC2 receptors. Research interest spans chronic inflammatory response syndrome (CIRS), pulmonary disease, autoimmune conditions, and COVID-19 respiratory failure. Its intravenous form, Aviptadil (Zyesami), showed a signal for 60-day survival benefit in an earlier phase 2b/3 trial (Youssef et al., 2022) and received FDA Fast Track and Orphan Drug designations, but the larger, subsequent NIH ACTIV-3b trial in critically ill COVID-19 patients (~460 participants) found no meaningful difference at its 90-day mortality endpoint (a different endpoint and follow-up length from the 60-day signal above, not directly comparable): 37% vs. 36% for placebo per the May 2022 DSMB interim announcement (the later published final paper reports 38% vs. 36%). The trial was discontinued for futility in May 2022; the FDA had already declined an Emergency Use Authorization request in November 2021 citing insufficient data. The nasal spray form is a compounding-pharmacy product used off-label under prescription, has never received FDA approval, and its efficacy evidence base for CIRS consists mainly of small, non-placebo-controlled case series. Vialdyne releases VIP as a lyophilized octacosapeptide (linear, 28-residue) against a ≥ 99.0% HPLC main-peak specification, with a batch-specific Certificate of Analysis covering RP-HPLC purity, mass-spec identity, water content, residual solvents, and endotoxin. Sequence / identity confirmation is documented on the released lot.
Applications & buyer fit
Cognitive and neuropeptide buyers are predominantly research labs running in vivo rodent studies. The dominant administration route in the literature is intranasal, these peptides are not meaningfully blood-brain-barrier permeable when delivered systemically. For in vivo workflows, endotoxin and microbial-limit testing is recommended at the COA stage so the bioassay readout is not confounded by contamination unrelated to the test article.
Sourced for
Buyer fit
Documentation that ships
Procurement note: For in vivo workflows, endotoxin and microbial-limit testing on the specific lot is recommended at the COA stage.
Primary buyer fit: academic and contract research laboratories.
Specifications
Regulatory note
Research-use-only reference material; not for human or veterinary use.
Selected literature
Frequently asked questions
Native VIP carries a C-terminal amide, and losing it costs most of the receptor affinity, so identity work has to resolve the amidated species from the free-acid byproduct of incomplete synthesis. The two differ by only about one mass unit at the C-terminus, which means the certificate should show high-resolution mass spectrometry landing on the theoretical amidated mass, not merely an approximate total, together with an RP-HPLC purity profile that separates and quantifies the free-acid impurity. Confirm net-peptide content as well, so the amidated peptide mass is distinguished from counter-ion and water in the vial before you dose.
VIP is supplied lyophilized and is best held sealed, desiccated, and frozen until use. In solution it is prone to the ordinary liabilities of a mid-length peptide, so reconstitute in a vehicle matched to its solubility, keep working dilutions cold, and aliquot to avoid repeated freeze-thaw that can erode activity across a binding-assay series. Because the compound acts at both VPAC1 and VPAC2 without distinguishing them, consistency of the dosed concentration is what makes results comparable between experiments; record preparation dates and treat aged stock as a more likely source of drift than lot-to-lot variation.
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