Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
VIP
Vasoactive intestinal peptide is a 28-amino-acid hormone first isolated from pig intestine in 1970 and identical in humans, pigs and rats.
Dosing & scaling, explained
The moderated mass amounts below are retained for comparison. Near-duplicates, mix-dependent volumes and device markings are excluded. This is educational source context, not a protocol or recommendation.
Mass amounts available for comparison
- Lower range100 mcgDose
Recorded example with no verified study backing; shown for amount literacy only.
- Mid range500 mcgDose
Recorded example with no verified study backing; shown for amount literacy only.
Only mcg or mg amounts are retained. The calculator derives mL, syringe units or pen clicks from the current vial strength, water volume and device.
No independently verified schedule
Evidence context
No clinical amount or schedule is inferred from this material. Source verification is pending, and every displayed amount remains educational context rather than guidance.
Storage, handling and interpretation
Product identity
Verify the exact compound, formulation and amount against the product label or certificate before calculation.
Storage & handling
Follow the product label, certificate and validated laboratory SOP; no universal storage assumption is applied here.
Prepared solutions
Label concentration and preparation date, use sterile technique where applicable, and follow a validated stability protocol.
Reported protocols for VIP
What published studies and recent community write-ups report about amounts, timing and course length. 8 clinical and 4 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical8 rows | |||||
| Zyesami phase 2b/3 trial in critical COVID-19 (NCT04311697)196 adults with COVID-19 respiratory failure on high-flow oxygen, non-invasive or mechanical ventilation at 10 US hospitals, randomized 2:1 | 50 pmol/kg per hour on day 1, 100 pmol/kg per hour on day 2 and 150 pmol/kg per hour on day 3 | One 12-hour infusion per day for 3 consecutive days | Intravenous infusion | 3 days, with follow-up to day 60Not applicable | Critical Care Medicine (PubMed)2022 |
| The primary endpoint of being alive and free of respiratory failure at day 60 was not met (odds ratio 1.6, 95% CI 0.86 to 3.11), although 60-day survival favored aviptadil (odds ratio 2.0, p = 0.035) and interleukin-6 fell by day 3. Mild to moderate diarrhea occurred in 32.8% of treated patients versus 1.5% on placebo, and 6.9% needed dose adjustments; the trial changed its sample size and analysis plan during the pandemic, which the authors acknowledge. | |||||
| NIH ACTIV-3b TESICO phase 3 trial (NCT04843761)461 hospitalized adults with COVID-19 acute hypoxemic respiratory failure at 28 US sites, median age 57, 94% in intensive care | 600 pmol/kg on day 1, 1,200 pmol/kg on day 2 and 1,800 pmol/kg on day 3 (the same 50, 100 and 150 pmol/kg per hour rates spread over 12 hours) | One 12-hour infusion per day for 3 days | Intravenous infusion, paused or stopped for hypotension or heavy diarrhea | 3 days, with follow-up to day 90Not applicable; the aviptadil arm was stopped for futility on 25 May 2022 | The Lancet Respiratory Medicine (PubMed)2023 |
| Aviptadil did not improve the six-category recovery outcome at day 90 (odds ratio 1.11, 95% CI 0.80 to 1.55) and 90-day mortality was 38% versus 36% on placebo. Mean arterial pressure ran 5 to 7 mmHg lower during infusions and flushing, hypotension and diarrhea were more common, so the trial is the strongest evidence that intravenous VIP does not help this population. | |||||
| Inhaled VIP for primary pulmonary hypertension, pilot study8 patients with primary pulmonary hypertension in Vienna | 200 mcg per day given as four inhalations (50 mcg each) | Four times daily | Inhalation | 3 months, with follow-up measurements at 24 weeksNone described | Journal of Clinical Investigation2003 |
| After three months mean pulmonary artery pressure fell from 59 to 46 mmHg, cardiac output rose from 4.7 to 6.4 L/min, pulmonary vascular resistance fell by about half and six-minute walk distance improved by 113 m, with no side effects reported. The study had no control group and only eight patients, and later single-dose work found a much smaller effect. | |||||
| Single inhaled dose during right-heart catheterization20 patients with pulmonary hypertension (9 arterial, 8 from lung disease, 3 thromboembolic) in Munich | 100 mcg | Single inhalation | Inhaled aerosol | Acute study onlyNot applicable | European Respiratory Journal (PubMed)2008 |
| The aerosol caused a small, short-lived and selective fall in pulmonary vascular resistance, with 6 of 20 patients improving by more than 20%, and no change in systemic blood pressure or side effects. The authors called the effect modest and asked for studies of higher doses and chronic use, which have not followed. | |||||
| Inhaled aviptadil for active sarcoidosis, phase 2 (DRKS00000184)20 patients with biopsy-proven, active pulmonary sarcoidosis in Freiburg | 50 mcg per inhalation | Four times daily | Inhalation through an ultrasonic nebulizer | 28 daysNot applicable | German Clinical Trials Register (DRKS)2017 |
| The German trial registry lists the regimen as 50 mcg of synthetic VIP four times a day for 28 days with bronchoalveolar lavage before and after. The published results (Prasse and colleagues, 2010) reported that inhalation was well tolerated, that TNF-alpha production by lavage cells fell and that regulatory T cells increased; the study was open-label with no placebo group and no clinical endpoint. | |||||
| Invicorp (aviptadil with phentolamine) for erectile dysfunction, UK licenceAdult men with erectile dysfunction of neurogenic, vasculogenic, psychogenic or mixed cause | 25 mcg aviptadil plus 2 mg phentolamine mesilate (one 0.35 mL ampoule) | Not more than once daily or three times a week | Direct intracavernosal injection; first injections given by trained staff | Ongoing as needed, with review about every 3 months early onErection should not last beyond one hour | Scottish Medicines Consortium2017 |
| In the main crossover study of 187 men, fewer achieved a full erection on aviptadil/phentolamine than on alprostadil during dose-finding (73% versus 83%), but moderate or severe adverse events (4.3% versus 12%) and injection pain (3% versus 28% of injections) were less common and facial flushing more common (16% versus 3%). This is the only marketed product anywhere that contains aviptadil, and it is not approved in the United States. | |||||
| Intranasal VIP in chronic inflammatory response syndrome, open-label study20 adults (11 women, 9 men, mean ages 51 and 48) with CIRS attributed to water-damaged buildings that had not resolved after the first 10 steps of the Shoemaker protocol | 50 mcg per spray | Four times daily, later titrated down to the lowest effective frequency and back up | Nasal aerosol, self-administered | At least 18 monthsAfter 6 months, 8 patients stayed at 3-4 doses a day, 4 used 1-2 a day, 3 used it only before exertion and 5 stopped | Health (Scientific Research Publishing)2013 |
| The authors reported that symptoms fell to control levels, that C4a, TGF-beta-1, MMP-9 and VEGF normalized, that regulatory T cells rose from 8.9 to 22.5 and that one patient had a transient lipase rise without pain. There was no placebo group, comparisons were against historical clinic controls, the lead author designed the protocol, and the paper is not indexed in PubMed. | |||||
| Intranasal VIP escalation protocol in the 2017 grey-matter studyCIRS patients treated by Shoemaker-protocol physicians, followed with NeuroQuant MRI | 50 mcg per 0.1 mL spray (500 mcg/mL compounded solution); one spray, rising to two sprays per dose | Four times daily for the first month, then two sprays four times daily each month if symptoms persisted | Intranasal, after a supervised test spray in the office | More than 12 weeks; patients continued while improvingNone described | Community resource2017 |
| The paper describes a single observed test dose, then one spray four times a day for a month before stepping up, and reports no dropouts for adverse events. It is an uncontrolled report in a non-indexed journal written by the protocol's developers and a compounding pharmacist. | |||||
| Community-reported4 rows | |||||
| Compounded nasal spray regimens compared | 50 mcg per spray (500 mcg/mL); 200 mcg per day at one spray four times daily, 400 mcg per day if both nostrils or two sprays are used | Four times daily, alternating nostrils | Intranasal, first dose given in clinic with lipase and TGF-beta-1 checked 15 minutes later | About 3 months minimum in protocol summaries; some patients continue for 18 months or moreTaper to twice daily for 30 days, then once daily for 30 days, then stop | Community resource2026 |
| This September 2026 explainer tabulates five different regimens from the 2013 trial, protocol summaries, pharmacy labels and clinics, and points out that the main disagreement is whether a dose means one nostril or both. It grades the evidence as low, notes that VIP sat in FDA 503A compounding Category 1 (under evaluation) as of May 2026, and lists lipase, blood pressure and pregnancy as the main monitoring and exclusion points. | |||||
| Research-vial subcutaneous dosing table | 50 mcg to start; 100 mcg standard; 200 mcg upper | Once daily for 1-2 weeks to start, then once or twice daily; a clinic-style 200 mcg five days a week is also listed | Subcutaneous from a 10 mg vial reconstituted with 3 mL bacteriostatic water (3 units per 100 mcg) | Open-ended; planning tables cover 4-12 weeksFrequency adjusted to response rather than fixed cycles | Community resource2026 |
| This June 2026 guide separates injectable research use from the compounded nasal spray and says the two are not interchangeable. It states that there is no approved or trial-validated subcutaneous VIP protocol and that the figures are community conventions, and lists flushing, dizziness and blood-pressure drops as reasons to stop. | |||||
| Evidence-focused 2026 review with reconstitution math | 50-200 mcg per day subcutaneously; 50 mcg per spray intranasally, rising to 100 mcg per spray | Once or twice daily (subcutaneous); four times daily (nasal) | Subcutaneous (5 mg vial in 2 mL gives 25 mcg per unit) or compounded nasal spray | Not fixed; the nasal protocol steps up after one month if labs have not normalizedNone described | Community resource2026 |
| This guide, last reviewed June 2026, walks through the trial record (pulmonary hypertension, sarcoidosis, two COVID-19 trials) and concludes that no completed phase 3 supports any VIP formulation and that injectable self-use has no trial backing at all. It flags that TESICO showed more hypotension (58% versus 41%) and diarrhea (40% versus 11%) than placebo, and treats the CIRS evidence as one open-label case series. | |||||
| Dosage chart built around the one-minute half-life | 25 mcg (conservative), 50 mcg (common) or 100 mcg (upper) per injection | Per dose; no validated schedule given | Subcutaneous from a 5 mg vial in 2 mL bacteriostatic water (2 units per 50 mcg) | Not specified; the authors argue a 5 mg vial outlasts any realistic courseNone described | Community resource2026 |
| A July 2026 chart that refuses to present a titration schedule because human infusion studies measured a plasma half-time of about one minute, which is why every controlled trial used continuous infusion. It warns that at 2,500 mcg/mL a one-unit syringe error equals an entire conservative dose and that standing quickly, heat, alcohol and blood-pressure drugs all compound the vasodilation. | |||||
How a course is commonly described
- Day 1: supervised test doseCommunity-reported
In the CIRS protocol the first 50 mcg spray is given in the clinic after baseline bloodwork, with TGF-beta-1 and lipase rechecked 15 minutes later. Protocol summaries make a normal lipase, a negative deep nasal culture, a passed contrast-sensitivity test and no ongoing building exposure preconditions for starting.
- Month 1: 50 mcg four times dailyClinical
The 2017 protocol paper describes one spray four times a day, alternating nostrils, for the first month, which matches the regimen used in the 2013 open-label study. Clinic guides place easing of air hunger at 2 to 4 weeks, but that timing comes from practice rather than controlled data.
- Months 2-6: titrationClinical
If symptoms and labs have not settled after a month, the 2017 paper steps up to two sprays four times daily; the 2013 study instead titrated downward after six months to find the lowest frequency that held the benefit and then back up. By the end of that study 8 of 20 patients still used it 3 to 4 times a day and 5 had stopped altogether.
- Taper and stopCommunity-reported
Protocol summaries describe stepping down to twice daily for 30 days and then once daily for 30 days before stopping, with lipase checked during the taper and again at six months. Some patients in the 2013 cohort stayed on the spray for 18 months or longer.
- Clinical comparison: infusions and inhalationClinical
The controlled trials look nothing like the nasal or injection schedules: three days of 12-hour intravenous infusions in intensive care for COVID-19, four inhalations a day for 4 weeks in sarcoidosis or 3 to 6 months in pulmonary hypertension, and a single intracavernosal injection as needed for erectile dysfunction. The one adequately powered trial, TESICO, found no benefit and more hypotension and diarrhea.
- Human infusion studies measured a plasma half-life of roughly one minute, which is why trials used continuous 12-hour infusions and why nasal and inhaled regimens repeat four times a day. A once-daily subcutaneous injection cannot hold a systemic level, and no trial has tested injected VIP outside hospital.
- The CIRS nasal-spray evidence is one open-label study of 20 patients and one uncontrolled MRI report, both written by the protocol's developers, and CIRS itself is not an accepted diagnosis in mainstream medicine. The larger trial record (TESICO) is negative.
- No VIP product is approved in the United States. Invicorp is licensed in the United Kingdom only as a combination for erectile dysfunction, and compounded nasal spray depends on FDA compounding policy that can change. The rows above record what sources report, not endorsements of use.
Sources for this section (13)
- The Use of IV Vasoactive Intestinal Peptide (Aviptadil) in Patients With Critical COVID-19 Respiratory Failure: Results of a 60-Day Randomized Controlled Trial
- Intravenous aviptadil and remdesivir for treatment of COVID-19-associated hypoxaemic respiratory failure in the USA (TESICO): a randomised, placebo-controlled trial
- Vasoactive intestinal peptide as a new drug for treatment of primary pulmonary hypertension
- Inhalation of vasoactive intestinal peptide in pulmonary hypertension
- Aviptadil (synthetic VIP) inhalation in active pulmonary sarcoidosis (DRKS00000184)
- Inhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosis
- Aviptadil / phentolamine 25 micrograms / 2 mg solution for injection (Invicorp): SMC No 1284/17
- Vasoactive intestinal polypeptide (VIP) corrects chronic inflammatory response syndrome (CIRS) acquired following exposure to water-damaged buildings
Plus 5 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Overview
Vasoactive intestinal peptide is a 28-amino-acid hormone first isolated from pig intestine in 1970 and identical in humans, pigs and rats. It is made in the gut, lungs, brain and immune cells, acts through the VPAC1 and VPAC2 receptors to relax blood vessels, airways and gut smooth muscle, and damps several inflammatory pathways; it disappears from plasma within a minute or two, so clinical programs have used continuous infusions, inhalation or nasal sprays. The synthetic form, aviptadil, has been tested by inhalation in pulmonary hypertension and sarcoidosis and intravenously in COVID-19 respiratory failure under the names RLF-100 and Zyesami, where a 196-patient phase 2b/3 trial missed its primary endpoint and the larger NIH TESICO trial was stopped for futility. No VIP product is approved in the United States; a fixed combination with phentolamine (Invicorp) is licensed in the United Kingdom for erectile dysfunction, compounded 50 mcg nasal sprays are prescribed in the Shoemaker protocol for chronic inflammatory response syndrome, and research vials are sold online with community injection doses of 50-200 mcg.
What researchers are exploring
These themes organize the educational information currently available. Individual claims remain under source review and are not treatment claims.
- 1
Research on VIP
VIP, primarily produced by immune nerve fibers in blood vessels of the central and peripheral nervous systems and the heart, serves as an important player in regulating inflammation.…
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
Research on VIP
VIP, primarily produced by immune nerve fibers in blood vessels of the central and peripheral nervous systems and the heart, serves as an important player in regulating inflammation.…
Amounts recorded for VIP
These amount records are independent from vial strength, reconstitution volume and measuring device. A recorded source is not the same as study backing, and these values are not recommendations.
- 1Dose · lower endpointSign in for schedule, duration and source context.100 mcg
- 2Dose · upper endpointSign in for schedule, duration and source context.500 mcg
Chemistry identifiers
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Sequence
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
Also listed as
Aviptadil, Zyesami, RLF-100, Invicorp (aviptadil + phentolamine), Vasoactive intestinal octacosapeptide, VIP (human, porcine, rat), UNII A67JUW790C, GTPL10891
InChIKey
VBUWHHLIZKOSMS-RIWXPGAOSA-N
IUPAC name
(2S)-4-amino-2-[[(2S)-2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-4-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-5-amino-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-4-amino-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-amino-3-(1H-imidazol-5-yl)propanoyl]amino]-3-hydroxypropanoyl]amino]-3-carboxypropanoyl]amino]propanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]-4-oxobutanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-hydroxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]hexanoyl]amino]-5-oxopentanoyl]amino]-4-methylsulfanylbutanoyl]amino]propanoyl]amino]-3-methylbutanoyl]amino]hexanoyl]amino]hexanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-4-methylpentanoyl]amino]-4-oxobutanoyl]amino]-3-hydroxypropanoyl]amino]-3-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-oxobutanoic acid
Limitations and unknowns
Sources
1 link carried over from the earlier page, awaiting verification.