VIP

Research summary

Vasoactive Intestinal Peptide (VIP) is a naturally occurring neuropeptide that relaxes vascular smooth muscle and inhibits proliferation of pulmonary vascular smooth muscle cells, properties that made it a candidate for research into pulmonary arterial hypertension, a disease marked by abnormal narrowing of lung blood vessels.

Early pilot studies in small groups of pulmonary hypertension patients showed increased cardiac output and improved physical capacity with inhaled VIP. However, a larger, controlled Phase 2 trial of 56 patients found no clinical benefit, and some patients on long-term treatment developed antibodies to VIP. The compound's early promise has not been confirmed in larger controlled trials.

Sources: Journal of Clinical Investigation, 2003 (Petkov et al.); European Respiratory Journal, 2008. Findings from published research —not a claim about this product, and not evidence of safety or effectiveness for human use.