intestinal peptide FAQ

Verify storage temperature immediately. Exposure above 8°C causes progressive degradation even in lyophilized form, and reconstituted VIP degrades faster at room temperature. If the vial was stored correctly, the issue may be incomplete reconstitution. VIP requires gentle swirling, not vortexing, and full dissolution can take 5–10 minutes. Use bacteriostatic water, not saline, to prevent aggregation. If degradation is confirmed, discard the vial. Degraded peptide produces inconsistent results and cannot be rescued.

Oral bioavailability of native vasoactive intestinal peptide is essentially zero. The peptide is degraded by gastric acid and intestinal proteases before systemic absorption occurs. Intranasal delivery achieves limited CNS penetration through olfactory pathways, bypassing the blood-brain barrier partially, but systemic exposure remains minimal. Modified analogs with protease resistance or absorption enhancers can improve non-injectable delivery, but these are experimental and not commercially standardized. For reliable systemic or CNS effects, subcutaneous or intravenous administration remains necessary.

Administer VIP during the resolution phase rather than the initiation phase. Its efficacy shifts from prevention to repair. Post-peak VIP still promotes M2 macrophage polarization and Treg expansion, which accelerates inflammation resolution and tissue remodeling. Sepsis models show reduced efficacy when VIP is given after cytokine surge, but chronic inflammation models (arthritis, colitis) demonstrate benefit even when treatment begins after disease establishment. The therapeutic window narrows as the inflammatory cascade matures.