CIRS nasal spray
Trial- Dose
- 50 mcg (one spray)
- How often
- 4× daily
- How long
- 18 months or more, later tapered
Open-label study of 20 patients, only after earlier CIRS steps, a low-mold home and a negative nasal staph (MARCoNS) test.
Human studiesNeuropeptide
VIP
Vasoactive intestinal peptide, aviptadil
- Common dose
- 50 mcg nasal, 4× daily
- Cycle
- Continuous
- Vial sizes
- 5 mg
A 28-amino-acid neuropeptide found in the gut, lungs and brain. It widens blood vessels and calms inflammation.
Evidence. Small human studies of nasal VIP in chronic inflammatory response syndrome (CIRS). In critical COVID-19, IV VIP (aviptadil) missed its main goal in a 196-person trial and showed no benefit in a 461-person NIH trial. Approved only inside a combination product for erectile dysfunction in some European countries.
Status
- Approval
- Not approved in the US. As aviptadil, it is approved only with phentolamine (Invicorp) for erectile dysfunction in several European countries.
- Sport (WADA 2026)
- Not banned in sportNot named on the 2026 list.
Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026.
Protocol
Trial
CIRS open-label study, 20 patients
Intranasal: 50 mcg 4× daily (one spray each time), for 18 months or more, then tapered.
- Frequency
- 4× daily (nasal)
- Route
- Intranasal (studied)
- Cycle
- Continuous in the study (18 months).
Continuous, shown over 26 weeks
Common protocols
The ways VIP is most often run, each tagged with where it comes from.
IV aviptadil, COVID ICU
Trial- Dose
- 50–150 pmol/kg/hr, stepped up
- How often
- 12-hour IV infusions
- How long
- Short hospital course
Tested in critical COVID-19 respiratory failure; two randomized trials (196 and 461 patients) found no clear benefit. Hospital only; not approved.
Dosing by body weight
Trial50–150 pmol/kg/hr. IV aviptadil in critical COVID-19, 12-hour infusions stepped up from 50 to 150 (NCT04311697). Hospital only.
Taking it
Where it goes
CIRS use: one 50 mcg nasal spray per dose. IV aviptadil was given only in hospital trials.
If you miss a dose
No published rule. The CIRS study used four doses a day; if one is missed, take the next on schedule rather than doubling up.
What to expect
- Within 2 months
In the CIRS study, the rise in lung artery pressure during exercise fell below 8 mmHg in all 20 patients.
Trial - By 18 months
Symptoms fell to the level of healthy controls and inflammation markers normalized (open-label, no placebo group).
Trial - Throughout
No one in the CIRS study quit because of side effects over 18 months.
Trial
Side effects and what to do
Flushing, low blood pressure or lightheadedness (VIP widens blood vessels; mainly with systemic doses)
Sit or lie down; stop and get help if you faint.
Raised lipase without pain (1 of 20 in the CIRS study)
It settled without stopping; doctors checked lipase during treatment.
Watery diarrhea (a known effect of high VIP levels)
Stop and seek care if it’s severe or comes with dizziness.
Stop and get medical help
Fainting or very low blood pressure, chest pain, severe or ongoing diarrhea, or strong belly pain (especially with a high lipase).
Tracking and pairing
Worth tracking
- Blood pressure and pulse
- Lipase (checked in the CIRS study)
- CIRS markers the study tracked: C4a, TGF beta-1, MSH, VEGF, MMP9
- Estradiol and testosterone (tracked in the study)
Often paired with
Usually run on its own.
Human studies
5 key published human studies, with how many people took part. Animal studies aren’t listed here.
-
In COVID-19 respiratory failure, no benefit at day 90 (OR 1.11, 95% CI 0.80 to 1.55); deaths were 38% vs 36% with placebo.
- Design
- Randomized placebo-controlled trial (TESICO, NIH ACTIV-3b)
- Dose
- IV aviptadil as 12-hour infusions, 600 to 1,800 pmol/kg a day
- Length
- 3 days
Brown et al., Lancet Respir Med 2023 (TESICO), PMID 37348524
-
In critical COVID-19, the main endpoint (alive and free of respiratory failure at day 60) was not met (OR 1.6, 95% CI 0.86 to 3.11).
- Design
- Randomized placebo-controlled trial (2:1)
- Dose
- IV aviptadil
- Length
- 3 days
Youssef et al., Crit Care Med 2022, PMID 36044317
-
In erectile dysfunction, 75.1% responded to VIP with 1 mg phentolamine vs 12% to placebo (P<0.001); flushing after 33.9% of injections.
- Design
- Double-blind placebo-controlled trial, VIP with phentolamine
- Dose
- 25 mcg VIP with 1 or 2 mg phentolamine, injected into the penis
Sandhu et al., Int J Impot Res 1999, PMID 10356669
-
In CIRS patients who had finished 10 prior treatment steps, symptoms fell to control levels in all 20 and inflammatory markers normalized.
- Design
- Open-label uncontrolled study
- Dose
- 50 mcg intranasal 4 times a day
- Length
- At least 18 months
Shoemaker et al., Health 2013, doi:10.4236/health.2013.53053
-
In active sarcoidosis, inhaled VIP was well tolerated and lowered TNF-alpha release from lung lavage cells.
- Design
- Open-label phase 2 study
- Dose
- Inhaled (nebulized) VIP
- Length
- 4 weeks
Prasse et al., Am J Respir Crit Care Med 2010, PMID 20442436
Mixing your vial
| Vial | Water | Common dose | Draw | Strength | Action |
|---|---|---|---|---|---|
| 5 mg | 2 mL | – | – | 2.5 mg/mL |
The study’s spray delivered 50 mcg per puff. At a typical 0.1 mL per spray, that’s a 0.5 mg/mL solution, so a 5 mg vial makes 10 mL at that strength.
There’s no established per-injection amount for VIP, so the table shows strength only.
Datasheet
- Half-life
- about 1 to 2 minutes TrialPlasma, after IV infusion in healthy volunteers. One study also found a slower second phase of about 21 minutes.
- Type
- Peptide, 28 amino acids
- Molecular weight
- 3,325.8 g/mol
- Formula
- C147H238N44O42S
- Sequence
- HSDAVFTDNYTRLRKQMAVKKYLNSILN
- Storage before use
- Freezer (about −20 °C) for long-term storage; fridge for short periods.
- After mixing or opening
- Fridge (2–8 °C); use within about 4 weeks.
- Half-life: Domschke et al., Gut 1978, PMID 730072; Holm-Bentzen et al., Scand J Gastroenterol 1981, PMID 16435487
- Molecule: UniProt P01282 (C-terminal amide); weight computed. PubChem CID 16132300 (aviptadil) shows the non-amidated form, 3326.8.
- Storage: Community Common practice. For comparison, Invicorp (with phentolamine) is kept at 2–8 °C, not frozen, and used within 24 hours out of the fridge.
Cautions
- A strong blood-vessel widener: flushing and low blood pressure are possible with systemic doses.
- The CIRS study treated patients only after other conditions were met, including no ongoing mold exposure.
- Not FDA-approved in any form.
Questions
What is VIP?
A 28-amino-acid neuropeptide found in the gut, lungs and brain. It widens blood vessels and calms inflammation.
Is VIP FDA-approved?
Not approved in the US. As aviptadil, it is approved only with phentolamine (Invicorp) for erectile dysfunction in several European countries.
What is the usual VIP dose?
From human studies (CIRS open-label study, 20 patients): Intranasal: 50 mcg 4× daily (one spray each time), for 18 months or more, then tapered. These are the amounts sources reference, not recommendations.
What is the half-life of VIP?
About 1 to 2 minutes, measured in human studies. Plasma, after IV infusion in healthy volunteers. One study also found a slower second phase of about 21 minutes.
How should VIP be stored?
Before mixing: Freezer (about −20 °C) for long-term storage; fridge for short periods. After mixing: Fridge (2–8 °C); use within about 4 weeks. This is common practice; no product label covers it.
Is VIP banned in sport?
No. Not named on the 2026 list.
Has VIP been studied in people?
Yes. The human studies section lists 5 published studies. The largest, from 2023, included 461 people. In COVID-19 respiratory failure, no benefit at day 90 (OR 1.11, 95% CI 0.80 to 1.55); deaths were 38% vs 36% with placebo.
Sources
- Shoemaker et al., intranasal VIP in CIRS (Health 2013)
- Invicorp (aviptadil/phentolamine) patient leaflet (UK)
- Brown et al., IV aviptadil in COVID-19 respiratory failure, TESICO (Lancet Respir Med 2023) PMID 37348524
For the protocol details
- Intravenous aviptadil for critical COVID-19 with respiratory failure, NCT04311697 (ICH GCP registry)