Because VIP is a potent vasodilator, its most predictable effects are cardiovascular: flushing, a drop in blood pressure, lightheadedness, and headache. These follow directly from the peptide's mechanism rather than from any single study.[1][2]
Reviewed for accuracy · Last reviewed July 8, 2026For the intranasal community use, added local effects such as nasal irritation are plausible, but the safety evidence is limited: the CIRS studies are small, open-label, and uncontrolled, so they cannot reliably characterize how often adverse effects occur. In the clinical aviptadil trials, the drug was generally described as tolerated, but those were also modest in size.
The hedged reading is that the acute vasodilatory effects are well understood from VIP's biology, while the longer-term safety of repeated intranasal dosing in the community context is essentially uncharacterized.
Vasodilatory effects like flushing and lightheadedness are often dose-related. Anyone experiencing fainting, chest pain, or an irregular heartbeat should stop and seek medical advice rather than adjust a dose independently.
This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. Talk to a doctor before starting any compound.