Peptide field guide
Vasoactive intestinal peptide (VIP)
Vasoactive intestinal peptide (VIP) is an endogenous neuropeptide hormone involved in vasodilation, smooth muscle relaxation, and immune signaling. A 2026 preclinical paper reported VIP-induced autophagy and cytotoxicity in renal cell carcinoma models via a proposed SIRT3-dependent pathway.
What it is
Vasoactive intestinal peptide (VIP) is an endogenous peptide best known for roles in the nervous system and gut, including effects on smooth muscle tone, secretion, blood flow, and immune signaling.
VIP signals primarily through the GPCRs VPAC1 and VPAC2 (and related receptors), and it is widely studied in physiology.
Why people care about it
VIP is interesting because it sits at the intersection of:
- neurobiology (neuropeptide signaling)
- inflammation and immune modulation
- vascular and smooth muscle physiology
It also occasionally appears in oncology discussions, where peptide receptors can sometimes be exploited for imaging or targeted delivery, and where peptide signaling can have context-dependent effects.
What we know vs what we don’t know
What we know:
- VIP is a well-characterized endogenous peptide with established receptor biology.
- A 2026 preclinical report linked VIP treatment to autophagy-associated signaling and cytotoxicity in renal cell carcinoma models.
What we don’t know:
- Whether VIP has a consistent anti-tumor effect across cancers (peptide signaling can flip direction depending on context).
- Whether the reported RCC findings translate to in vivo efficacy with a usable safety window.
Latest updates
- 2026-04-01: Preclinical report: VIP induced autophagy and cytotoxicity in renal cell carcinoma models, proposed SIRT3-dependent signaling. https://pubmed.ncbi.nlm.nih.gov/41891524/ (DOI: https://doi.org/10.1002/jbt.70815)
Safety reality
VIP is a bioactive peptide hormone, not a supplement. It is not an approved cancer therapy. Treat any non-regulated product claims as high risk.