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Pick up to three peptides to see how their mechanisms, studied uses and evidence levels differ. Rows where the entries disagree are marked with a blue edge.
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Comparison
VIP (vasoactive intestinal peptide)
Cognitive & neuro
Evidence level
Anecdotal evidence
Approval status
Investigational
Mechanism of action
- 1.Activates VPAC1 and VPAC2 receptors, raising cAMP in target cells.
- 2.Shifts circadian clock gene expression in the suprachiasmatic nucleus.
- 3.Dampens inflammatory signalling in microglia and macrophages.
- 4.Relaxes vascular and bronchial smooth muscle.
- 5.Modulates learning-related plasticity in hippocampal slices.
Studied for
- Circadian rhythm and sleep research
- Neuroinflammation in animal models
- Pulmonary disease and sarcoidosis with inhaled aviptadil
- Erectile dysfunction with injectable aviptadil in some countries
Reported effects
- Clear vasodilation and flushing in humans
- Cognitive or memory effects are not established in people
- Preclinical anti-inflammatory effects in the brain
- Hypotension limits systemic dosing
Side effects
- Flushing
- Hypotension
- Tachycardia
- Headache
- Dizziness
Research protocol
Research context only - brain applications are experimental. Inhaled and injectable forms used in trials delivered microgram to nanogram per kilogram doses, and central nervous system studies have mostly been intranasal or intracerebroventricular in animals. No human cognitive protocol exists.
Research context only
Evidence justification
Human data exist for vascular and lung effects, but nothing in humans supports cognitive claims; those rest on animal and cell work.