Vasoactive intestinal peptide (VIP) is a 28-amino-acid signaling peptide first isolated from hog small intestine in 1970, noted for widening blood vessels.
Said and Mutt reported in Science in 1970 that the peptide caused systemic vasodilation, lower blood pressure, increased cardiac output and respiratory stimulation (Said and Mutt, 1970). VIP belongs to the same peptide superfamily as glucagon, secretin and growth hormone-releasing hormone. It acts through the VPAC1 and VPAC2 receptors, and a 2012 IUPHAR review describes roles in circadian rhythm, immunity, inflammation and insulin secretion (British Journal of Pharmacology, 2012).
Aviptadil, a synthetic form of human VIP, is the version tested in recent trials (Trials, 2022). The NIH-funded TESICO trial randomized 471 adults with COVID-19 respiratory failure at 28 US sites between April 2021 and May 2022. Intravenous aviptadil did not improve 90-day outcomes compared with placebo: 38% of the aviptadil group and 36% of the placebo group had died by day 90 (Lancet Respiratory Medicine, 2023).
No VIP or aviptadil product appears in FDA’s approved-drug database, but FDA lists VIP in Category 1, the bulk substances still under evaluation for compounding.
Category 1 of FDA’s 503A list, updated May 14, 2026, includes vasoactive intestinal peptide (FDA 503A categories). For Category 1 substances, FDA says it does not intend to take action against a compounder when the conditions in its interim guidance are met (FDA). That policy covers state-licensed pharmacies and licensed physicians compounding for patients. It does not turn research-labeled vials into approved or compounded medicine.
A compounded VIP prescription comes from a state-licensed pharmacy working under that policy. A research vial comes with only the seller’s label, which states what the seller intended to supply rather than what a lab measured. A third-party result showing identity and purity for that batch is the only independent check.
Before trusting any VIP label, check that batch’s published result in our latest tests or in Janoshik's public results database. No results are published for VIP yet in our index. When the first published result arrives, a vendor leaderboard appears above.