What it is
VIP stands for Vasoactive Intestinal Peptide. It is a peptide made of 28 amino acids. The body makes it in nerve cells of the gut and brain, in immune cells, and in the airways. It was first found in pig intestine in 1970. It was named for its ability to widen blood vessels. It acts on two receptors called VPAC1 and VPAC2. The lab-made version used in drug trials is called aviptadil. It has the same sequence as the natural peptide. Other names: Aviptadil, RLF-100, Zyesami.
What researchers study it for
- Lung failure in critical COVID-19
- Inflammation signals from immune cells
- Sarcoidosis of the lungs
- Arthritis in mice
- Blood vessel widening
- The body's daily sleep and wake cycle
What the studies found
1. It was found in pig intestine and widened blood vessels.
This 1970 study pulled VIP out of pig small intestine. It widened blood vessels and lowered blood pressure in animals. Later work found it in nerve cells all over the gut, brain, and airways. Animal data.
2. It left human blood in about 1 minute.
This 1978 study gave 4 healthy adults VIP by IV at three levels. After the drip stopped, blood levels dropped by half in about 1 minute. The highest level caused face flushing, a faster pulse, and bigger swings in blood pressure. Researchers concluded VIP acts near where it is released, not as a hormone carried in the blood. Human data.
3. It prevented and reduced arthritis in mice.
This 2001 study used a mouse model of arthritis. VIP given early stopped arthritis from starting. VIP given later reduced arthritis that was already there. It lowered the immune attack on joints and lowered inflammation signals at the same time. Joint damage dropped. Animal data.
4. Breathing it in lowered an inflammation signal in lung sarcoidosis.
A 2010 trial gave 20 people with active sarcoidosis VIP by inhaler for 4 weeks. Lung immune cells made less TNF-alpha, a main inflammation signal. Regulatory T cells, which calm the immune system, went up in the lungs. It was well tolerated. The trial had no placebo group. Human data.
5. It missed its main goal in critical COVID-19.
A 2022 trial gave 196 people with COVID-19 lung failure IV aviptadil or placebo over 3 days. The main goal, being alive and off breathing support at day 60, did not reach statistical significance. A secondary analysis found treated patients had 2 times the odds of being alive at day 60. The inflammation signal IL-6 dropped by day 3. No serious side effects were tied to the drug. A missed main goal means the benefit is not proven. Human data.
How much research exists
Decades of lab and animal studies. A few small human studies and one larger randomized trial. No large trial has met its main goal.
Facts
- Formula: C147H238N44O42S
- Weight: about 3326 g/mol
- CAS number: 37221-79-7
- Sequence: HSDAVFTDNYTRLRKQMAVKKYLNSILN-NH2
- Time in the blood: about 1 minute
- Storage: powder in the freezer. Once mixed, keep in the fridge. Avoid freezing and thawing again and again.
Legal status
Not approved by the FDA for any use. The COVID-19 program did not lead to approval. In the United Kingdom, a mix of aviptadil and phentolamine called Invicorp is approved as a prescription injection for erectile dysfunction.
For research use only. Not for human use. Nothing here is medical advice.