VIP

What people use it for

• Erectile dysfunction (with phentolamine, some countries)
• Lung inflammation (clinical research)
• Chronic inflammatory response syndrome (compounded nasal spray, popular use)

What VIP does in the body

Found throughout the gut, lungs and brain. It widens blood vessels, relaxes smooth muscle in the airways and gut, and dampens inflammatory immune signalling.

Strength of evidence

Limited to moderate depending on use; a large trial in COVID-19 respiratory failure did not lead to approval.

Look up the evidence

• Reviews on PubMed: Summaries of the published research
• Clinical trials on PubMed: Published studies in people
• ClinicalTrials.gov: Registered trials, past and ongoing
• Prescribing information (DailyMed, US): Official US label
• Patient leaflets (emc, UK): Official UK product information

Live searches of official databases. New to the terms? See the glossary.

Reported side effects & risks

• Flushing
• Low blood pressure, dizziness
• Diarrhea
• Fast heart rate

Who should avoid it or take extra care

• Low blood pressure or heart rhythm problems
• Pregnant or breastfeeding

Not a complete list. Check with a doctor or pharmacist about your own health and medicines.

Regulatory status

Approved in some European countries in combination with phentolamine for erectile dysfunction. Not approved in the US.

How it's taken

Route: Drip into a vein, inhaled, or injection

How long it lasts (half-life): About 1–2 minutes

Storage

Unreconstituted (powder) vials are usually kept refrigerated or frozen and away from light. Once mixed with bacteriostatic water, keep refrigerated and do not freeze; follow the supplier's stated beyond-use date.