VIP

Status Not approved as a standalone drug in this form; engineered analogues have been studied under FDA-regulated trials, none completed to approvalBest evidence E3Sources checked 2026-09-18

VIP is a real 28-amino-acid human hormone with a one-to-two-minute plasma half-life. Its Western human trials are of engineered long-acting analogues or synthetic copies, for COVID-19 ARDS and pulmonary arterial hypertension, not of periodic self-injection for general immune or wellness use.

Identity

Sequence: 28-amino-acid endogenous human neuropeptide (His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn)

What it is

Vasoactive intestinal peptide (VIP) is a naturally occurring 28-amino-acid human neuropeptide hormone, produced throughout the gut, lungs, brain and immune system, with roles in smooth-muscle relaxation, vasodilation, secretion and immune signalling. Unlike most compounds on this site, VIP is not a novel research molecule; it is the same sequence as an endogenous human hormone, and synthetic copies or engineered analogues of it have been developed as actual drugs.

Its native plasma half-life is extremely short, on the order of one to two minutes, which has driven drug development toward either continuous infusion, inhalation, or chemically modified long-acting analogues rather than simple periodic injection of the native peptide.

The human trial record, and what it is actually testing

Aviptadil, a synthetic form of the same 28-amino-acid VIP sequence, has been studied intravenously and by inhalation for COVID-19-associated acute respiratory distress syndrome, in randomized, placebo-controlled, double-blind multicenter trials; results and trial fates were mixed, and at least one large inhaled-aviptadil COVID-19 trial (AVICOVID-3) was withdrawn before enrolling.

Pemziviptadil (PB1046), a sustained-release engineered VIP analogue built for once-weekly subcutaneous dosing rather than the native peptide’s minutes-long half-life, was studied in pulmonary arterial hypertension in a randomized, double-blind, placebo-controlled Phase 2 trial that was later terminated, and separately in a small open-label Phase 1 dose-titration study in the same population.

Native VIP itself, unmodified, has been given to small numbers of healthy volunteers and migraine patients by controlled infusion in mechanistic headache studies at Danish academic centers, and has been studied observationally in COPD-associated pulmonary hypertension. These are short-infusion physiology studies, not treatment trials, and none used a self-administered subcutaneous injection schedule.

No registered trial located for this entry tests periodic subcutaneous self-injection of native VIP for general immune, sleep, longevity or inflammatory purposes, which is how this compound is most often described in circulating research-peptide material.

What is not known

Whether a periodic subcutaneous injection of native VIP, a peptide with a one-to-two-minute plasma half-life, produces any sustained effect at all. The engineered analogues that were built specifically to get around that short half-life used different chemistry and different dosing schedules than a simple injection of the native sequence.

Whether native VIP has any established role in the general immune, inflammatory or “mold illness” protocols it is sometimes marketed for. No trial located for this entry tested that use.

Long-term safety of native VIP given repeatedly outside a hospital or research infusion setting.

What is not known

Whether a periodic subcutaneous injection of native VIP produces any sustained effect, given its one-to-two-minute native plasma half-life. The engineered long-acting analogues that were actually trialled used different chemistry specifically to solve that problem.

Whether native VIP has any established role in general immune, inflammatory or “mold illness” protocols. No trial located for this entry tested that use.

Long-term safety of repeated native VIP dosing outside a hospital or research infusion setting.

Doses used in published research

No published study has administered this compound to a human being, so no dose appears in the literature and none has been established.

Amounts above record what a named source reported administering in a study. They are not a recommendation, not a protocol, and not instructions.

Converting a vial and a syringe into a draw volume is a separate, mechanical question from what amount to use. The reconstitution calculator does that arithmetic for peptide, HCG, and HGH vials.

What circulates E5

Figures reported online. Not dosing, not verified, not endorsed.
Reported use	Route	Amount reported	Frequency	Reported length
Immune/inflammatory support, general	Subcutaneous or intranasal	50 to 100 mcg per dose	Once or twice daily	Often cycled, weeks

Circulating material describes native VIP at 50 to 100 micrograms, subcutaneously or intranasally, once or twice daily. The clinical trials located for this entry either used continuous IV infusion, thrice-daily inhalation of 67 micrograms (in the inhaled aviptadil COVID-19 protocol), or a chemically modified once-weekly analogue built specifically because the native peptide does not last between doses. A twice-daily subcutaneous shot of native VIP does not resemble the pharmacology of any of those studied regimens, and no trial has tested whether it does anything at all.

Recorded as an observation about what is published elsewhere. No figure here is a dose, a protocol, or a recommendation, and nothing in this section is evidence that any amount is safe or effective.