Vasoactive intestinal peptide (aviptadil): uses and what the evidence shows
Vasoactive intestinal peptide, or VIP, is a peptide the body makes that relaxes blood vessels and smooth muscle. Its synthetic form is called aviptadil. The use that matters in clinics is as part of an injection for erectile dysfunction, usually combined with phentolamine, when pills have not worked. This page covers the evidence and the safety rules, including priapism.
Information current as of November 10, 2026. Educational only. Confirm everything here with your own clinician before starting, stopping or changing any medication.
At a glance
What it is
A 28 amino acid peptide hormone. Aviptadil is its synthetic form.
Main use
With phentolamine, injected into the side of the penis for erectile dysfunction that has not responded to pills.
What the evidence shows
A 308-man retrospective study found it effective in 59 percent. Flushing occurred in 22.5 percent.
Key risk
A prolonged, painful erection called priapism. It occurred in 0.3 percent in that study and is an emergency.
Other uses
Intravenous aviptadil was tested in COVID-19 respiratory failure. The main result was not statistically significant.
Pharmacy status
On the FDA’s interim Category 1 list, meaning pharmacies may prepare it while the FDA reviews it.
Uses
What VIP is used for
In sexual medicine, VIP combined with phentolamine is an injection given directly into the erectile tissue. It is a second-line choice. Pills such as tadalafil come first, because they are easier and have strong evidence. Injection therapy is considered when pills fail or cannot be used, for example after some prostate treatments or with certain medications.
Outside erectile dysfunction, aviptadil has been studied by IV and inhalation in lung disease and in COVID-19. Those uses are research, not approved care.
Erectile problems often signal something else, such as blood vessel disease, diabetes or low testosterone. Dr. Miranda starts there. See testosterone when low levels are part of the picture.
How it works
How the injection works
An erection needs the smooth muscle in the penis to relax so blood can fill the tissue. VIP relaxes that muscle and widens vessels. Phentolamine blocks a chemical that tightens them. The two work through different paths, which is the reason for combining them.
Intracavernosal injection usually needs first-dose teaching and a plan for what to do if an erection lasts too long. Dr. Miranda covers whether that can be done safely through telehealth and refers you to a local urologist when it cannot. This page does not give amounts.
Evidence
What the studies show
A retrospective study of 308 men treated with aviptadil plus phentolamine injections found the treatment effective in 59 percent. Flushing was reported by 22.5 percent, and priapism by 0.3 percent. It was not a randomized trial, and men who stayed in the program are not the same as all men who start.
A 2008 review of the combination product, known as Invicorp, discussed trials in men with erectile dysfunction, including some who had failed other treatments.
A randomized trial of IV aviptadil in COVID-19 respiratory failure did not meet its primary endpoint. That result does not bear on the erectile use, and it shows why a drug that works in one setting is not assumed to work in another. Results vary, and trials in different populations are not directly comparable.
Safety
Side effects and priapism
The most common effect is flushing of the face, from the blood vessel effect. Headache, a drop in blood pressure and a fast heartbeat can occur. Pain or a small bruise at the site is possible.
The serious risk is priapism. An erection lasting more than four hours is a medical emergency and needs the emergency department the same day. Waiting risks permanent damage.
Go to the emergency department for
- An erection that lasts four hours or more
- Chest pain, fainting or severe dizziness
- Swelling, hives or trouble breathing
Before you start
What a physician checks before injection therapy
Erectile dysfunction is often the first sign of something else. A visit starts with blood pressure, blood sugar, lipids and testosterone, and a review of medications, because several common drugs affect erections. Treating the cause can fix the problem, or at least make pills work.
The physician also asks what has already been tried. Tadalafil taken at the right time, with an empty stomach for some people, works for many men who thought pills had failed. Only when a fair trial has not worked does injection therapy make sense.
Some conditions raise the risk of a prolonged erection, including sickle cell disease and certain blood disorders, and some drugs interact with injection therapy. Tell the physician about every medication, including nitrates and blood thinners. If any of these apply, a urologist may be the better person to start treatment.
Regulatory status
VIP and pharmacies
VIP is on the FDA’s interim Category 1 list of bulk substances nominated for compounding. Category 1 means the FDA does not intend to take action against pharmacies that compound it under section 503A while it reviews the substance. That is not an approval.
Compounded drugs are not FDA-approved. The FDA does not evaluate them for safety, effectiveness or quality before they are sold.
Summit’s role
What Summit does with vasoactive intestinal peptide
Dr. Miranda prescribes vasoactive intestinal peptide after a physician evaluation. It is prepared by an independent, state-licensed pharmacy for you as a named patient, and only after a work-up of why the pills have not worked. Summit does not dispense or sell it, and it keeps no stock in the office.
Nothing on this page promises a prescription. If vasoactive intestinal peptide does not fit your history, labs and goals, you will hear why. See pricing for what the program includes, including labs.
Common questions
Questions people ask
Is VIP the same as aviptadil?
Aviptadil is the synthetic form of vasoactive intestinal peptide.
How does it compare with Viagra or Cialis?
It is a different route for men who cannot use pills or for whom pills have not worked. It is not a first choice.
What is priapism?
A prolonged erection, four hours or more. It is an emergency.
Is it FDA-approved?
No. Pharmacies can prepare it under the FDA’s interim Category 1 policy.
Do I need to see someone in person?
Injection therapy usually involves first-dose teaching. Dr. Miranda will say whether it can be done by telehealth or whether a urologist should start it.
Sources
Where this comes from
All retrieved November 10, 2026.
- Retrospective study of aviptadil plus phentolamine intracavernosal injection in 308 men. https://pubmed.ncbi.nlm.nih.gov/40192471/
- 2008 review of Invicorp (aviptadil plus phentolamine) for erectile dysfunction. https://pubmed.ncbi.nlm.nih.gov/18485029/
- Randomized trial of intravenous aviptadil in COVID-19 respiratory failure. https://pubmed.ncbi.nlm.nih.gov/36044317/
- FDA. Bulk drug substances nominated for use in compounding under section 503A: categories list, updated May 14, 2026. https://www.fda.gov/media/94155/download
Confirm with your provider. This page is general education, not medical advice, and it does not diagnose or treat anything. Every medication carries risks and is not right for everyone. Medication is prescribed only after a physician evaluation determines it is appropriate for you. Individual results vary and no outcome is guaranteed. Information current as of November 10, 2026.
Next step
Start with a physician evaluation
Dr. Miranda reviews your history, medications and goals before any decision about this injection.