VIP

VIP (Vasoactive Intestinal Peptide / Aviptadil)

In simple words

VIP is a natural 28-amino-acid peptide that reduces inflammation and widens the airways; its drug form is called aviptadil. It has been studied in severe lung damage from coronavirus infection, in pulmonary hypertension, and for protecting nerve tissue.

What this molecule is

His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn-NH₂. 28 aa. ~3326 Da. Secretin/glucagon superfamily.

Why it is studied

Multifunctional neuropeptide: anti-inflammatory, bronchodilating, neuroprotective. RCT of aviptadil in COVID-19 ARDS (Crit Care Med 2022). TESICO (Lancet Respir Med 2023, multicenter). Pulmonary hypertension. ED.

How it works

VPAC1 (↓pro-inflammatory cytokines of alveolar macrophages, ↑surfactant) + VPAC2 (↑Treg, ↓Th17). Bronchodilation via cAMP. Neuromodulation: ↓neuroinflammation, ↑neurogenesis. ↓ACE2/TMPRSS2 (via ADAM10).

Doses used in studies

Studies in COVID/ARDS used an IV infusion for 12 h × 3 days; in pulmonary hypertension — inhaled 100-200 mcg/day. T½ ~1 min — infusions only.

Combined with in studies

  • Remdesivir — the combination was studied in TESICO
  • KPV — different anti-inflammatory peptides
  • Thymosin Alpha-1

Level of evidence

Level A-B Human clinical trials. There are randomized controlled trials (RCTs), or the compound has been approved by a regulatory agency. The most reliable level. RCT in COVID and the multicenter TESICO trial.

Important to know

⚠️ TESICO was formally negative (primary outcome not met). T½ ~1 min → long infusions only. Not FDA-approved. NeuroRx ran into regulatory difficulties.

Studies in PubMed

  1. The Use of IV Vasoactive Intestinal Peptide (Aviptadil) in Patients With Critical COVID-19 Respiratory Failure: Results of a 60-Day Randomized Controlled Trial. (Crit Care Med, 2022)
  2. A negative trial for vasoactive intestinal peptide in COVID-19-associated acute hypoxaemic respiratory failure. (Lancet Respir Med, 2023)
  3. Vasoactive intestinal peptide as a new drug for treatment of primary pulmonary hypertension. (J Clin Invest, 2003)
  4. Vasoactive Intestinal Peptide (VIP) in COVID-19 Therapy-Shedding of ACE2 and TMPRSS2 via ADAM10. (Int J Mol Sci, 2025)
  5. A clinical trial of intracavernous vasoactive intestinal peptide to induce penile erection. (J Urol, 1990)
  6. Vasoactive intestinal peptide causes marked cephalic vasodilation, but does not induce migraine. (Cephalalgia, 2008)

Research peptides are laboratory reagents (Research Use Only). They are not medicines and are not intended for use in humans or animals.