What Is VIP (Vasoactive Intestinal Peptide)?

Also known as: Aviptadil, VIP nasal spray

Vasoactive intestinal peptide (VIP) is a 28-amino-acid neuropeptide found throughout the gut, lungs, brain and immune system. It relaxes smooth muscle, dilates blood vessels, and shifts immune signaling away from inflammation — a broad regulatory hormone rather than a targeted drug.

It is best known in two contexts: as the final stage of the Shoemaker protocol for chronic inflammatory response syndrome (mold illness), given as a compounded nasal spray; and as aviptadil, an IV formulation studied in pulmonary hypertension and COVID-19 respiratory failure.

What is VIP (Vasoactive Intestinal Peptide) studied for?

Side effects & safety

Flushing, low blood pressure, palpitations and headache from vasodilation; nasal irritation with spray use. Protocols typically require lab screening (lipase, MMP-9) before starting.

Legal & approval status

Not FDA-approved; available as a compounded nasal spray by prescription in the US. Aviptadil is approved in some countries for erectile dysfunction (combined) and investigational for respiratory indications.

Typical dosing at a glance

Commonly reported protocols use 50 mcg–200 mcg, 1–4x daily (nasal protocols use 50 mcg per spray), via intranasal or subcutaneous. For the mixing math — how much bacteriostatic water, exact syringe units, doses per vial — see the VIP (Vasoactive Intestinal Peptide) reconstitution calculator →

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Educational overview based on published research and commonly reported community protocols — not medical advice, and not an endorsement of any compound. Consult a licensed healthcare provider.