PepRank

VIP

Also: vasoactive intestinal peptide · aviptadil

EnergyGutNasal / IV

Potent vasodilating neuropeptide used in mould-illness (CIRS) protocols under a doctor.

Safety tier
Caution
strict bar
Positive
50%
of 30 reports
Per month
≈ €36–540
estimate
Rank
#13
of 61 research peptides

At a glance

Onset
Flushing and warmth within minutes of a spray; CIRS users mostly report benefits after weeks to 2-5 months, often after a rough first 2-4 weeks.
Lasts
Half-life in blood is a minute or two and the flush lasts ~10 minutes, so CIRS protocols spray up to 4 times a day for months.
Access
Prescription (compounded)
Strict case
Significant cardiovascular action (vasodilation/hypotension) and broad immunomodulation; a supervised CIRS therapy, not a general-health peptide.
Best effects
Energy and cognition in CIRS · lower inflammatory markers (CIRS) · visual contrast / fog lifting (anecdotal)
Downsides
Light-headedness · diarrhoea · flushing · needs slow titration
Typical use
CIRS protocol: titrated up to ~50 mcg nasal several times daily, only after exposure removal and lab-guided prerequisites. Users report 200–500 mcg/day (median 400 mcg, n=5).
Stacked with
Stacked with
Cholestyramine or Welchol (binders): The Shoemaker protocol puts VIP last, after binders, MARCoNS clearance and normal MMP-9; users who start early report the worst reactions. · Vilon: A long-COVID/ME-CFS nasal-spray combo from one widely shared post; its author later said only about a quarter of those who tried it responded. · KPV, BPC-157, LL-37 and thymosin alpha-1: Peptide-clinic gut and immune stacks for SIBO, MCAS and mould illness, in which VIP's own effect cannot be separated.

Safety

Watch
Potent vasodilator: hypotension and tachycardia · Broad immunomodulatory and secretory effects (VIPoma-like diarrhoea at high exposure)
Tier by safety barStrict CautionBalanced CautionEvidence only Caution
  • Seen harm1 of 3
  • Mechanism2 of 3
  • Data gap1 of 3
  • Silent harm1 of 3
  • Product1 of 3
Never if
Low blood pressure or heart disease · Pregnancy or breastfeeding (no human reproductive data)
Why each score
Seen harm 1/3
In the 461-patient TESICO trial of IV aviptadil in COVID respiratory failure, hypotension (58% vs 41%), diarrhoea and infusion reactions were more common and the composite safety outcome trended worse (OR 1.40, not significant); the CIRS nasal series of 20 reports no significant side effects, and the first-hand reports of weeks bedridden or returning seizures are confounded by CIRS itself. TESICO/ACTIV-3b: IV aviptadil in COVID respiratory failure, n=461 (hypotension 58% vs 41%) ↗Shoemaker et al. 2013: open-label nasal VIP in CIRS, n=20 ↗r/CIRS: bedridden for weeks after VIP (confounded by CIRS) ↗
Mechanism 2/3
A potent vasodilator that lowered mean arterial pressure by 5-7 mmHg during infusion, with broad secretory and immune effects (VIPoma-like diarrhoea at high exposure). TESICO/ACTIV-3b: IV aviptadil in COVID respiratory failure, n=461 (hypotension 58% vs 41%) ↗
Data gap 1/3
IV aviptadil has RCTs of 196 and 461 critically ill patients, and an intracavernosal combination is approved in the UK; nasal use for CIRS rests on one uncontrolled series of 20. TESICO/ACTIV-3b: IV aviptadil in COVID respiratory failure, n=461 (hypotension 58% vs 41%) ↗Youssef et al. 2022: IV aviptadil in critical COVID-19 respiratory failure, n=196 ↗Shoemaker et al. 2013: open-label nasal VIP in CIRS, n=20 ↗
Silent harm 1/3
Hypotension, flushing and diarrhoea appear within minutes to hours of a dose. TESICO/ACTIV-3b: IV aviptadil in COVID respiratory failure, n=461 (hypotension 58% vs 41%) ↗
Product 1/3
Usually a compounded prescription nasal spray within the CIRS protocol. Shoemaker et al. 2013: open-label nasal VIP in CIRS, n=20 ↗

User reports

All 30 reports →
Users report
In the CIRS/mould community some describe it as life-giving ('could see clearly for the first time in a decade'). Others notice nothing or say it 'helped but wasn't a cure'. Many react badly if not fully detoxed first, and some had to titrate over months while watching for low blood pressure.
Glowing 6Positive 9Mixed 2Nothing 4Negative 6Bad reaction 3
  • r/CIRS· · 74 upvotesOriginal ↗

    I’ve now started full-dose VIP and the first day I was on it, I could see clearly for the first time in a decade and my personality felt like it’s been coming back! A couple days later and I have energy!!!

    GlowingEnergy · Nasal

    CIRS with POTS, EDS, MCAS, CFS; started full dose after clearing MARCoNS under a Shoemaker practitioner

  • r/Raynauds· · 23 upvotesOriginal ↗

    Within 5 minutes I got a flushed feeling of warmth throughout my whole body and have not had a loss of circulation since.

    Glowing5 days at posting; cycled through winter

    Raynaud's; follow-up a year later reports no attacks or chilblains, alongside other peptides and supplements

  • r/CIRS· · 5 upvotesOriginal ↗

    I was told that the biofilm from MARCoNS prevents VIP from being absorbed...and my experience on VIP bore this out (got nothing).

    NothingNasal

    taken while MARCoNS were still present

Where to buy

All 4 offers →
Getting it
US compounding pharmacies make the nasal spray on prescription from CIRS (Shoemaker) practitioners; aviptadil itself is unapproved in the US, though an aviptadil-phentolamine injection is licensed for erectile dysfunction in the UK and Scandinavia. Grey-market vials are mixed into DIY sprays.

No listing can be priced, so the researchers estimate ≈ €36–540 a month.

No trusted shop in the EU lists it; every listing is on the buy page.

Studies

Evidence
Human RCTs — Aviptadil RCTs in COVID ARDS were negative; CIRS data are uncontrolled case series
2 more studies and 2 sources

Sources

Molecule

Sequence
HSDAVFTDNYTRLRKQMAVKKYLNSILN
Length
28 amino acids
Modifications
C-amide (28 aa)

Sequence

The peptide's chain of amino acids from its start (the N-terminus) to its end, one bead and one letter for each: A alanine, C cysteine, D aspartic acid, E glutamic acid, F phenylalanine, G glycine, H histidine, I isoleucine, K lysine, L leucine, M methionine, N asparagine, P proline, Q glutamine, R arginine, S serine, T threonine, V valine, W tryptophan, Y tyrosine. A modification such as an N-acetyl cap or a C-terminal amide changes how long it lasts in the body. Length tells related peptides apart, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4, and predicts neither effect nor safety.

Report grades

Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.

GlowingPositiveMixedNothingNegativeBad reaction

% positive

The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Peptides rank by this figure, those with no graded report yet after those with one, and Avoid ones after every other entry.

Researcher estimate

No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks after every peptide with graded reports until its own arrive.

Safety tier

Each peptide is tiered Clean, Caution or Avoid from its five risk axes under the chosen safety bar. An Avoid peptide carries a real risk of harm, a plausible route to serious harm rather than mere unpleasantness, so it stays listed with the reason but ranks behind every other entry, however good its reviews.

Safety bar

The safety bar sets how much risk it takes to rate a peptide Avoid. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.

Seen harm

Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.

Mechanism

A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.

Data gap

How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.

Silent harm

Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.

Product

The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin; taken by mouth or in the nose, a pack avoids the injection risks.

Evidence

The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.

Access

How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.

Price per month

Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. Prices are in euros at ECB rates of 2026-10-29, before shipping; the shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.

Dose users report

The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.

Shop trust

Each shop's trust on a 1–5 scale, read from its testing and its reputation: 1 for serious red flags (fabricated COAs, scam reports, impersonation, a closed shop), 2 for no public testing, a new shop or active complaints such as seized parcels, 3 for its own COAs or a short track record, 4 for verified third-party testing or a strong reputation, and 5 for third-party batch reports that name the shop, with years of good independent reputation. A shop without a score counts third-party batch testing as 4, its own COAs as 3 and no public tests as 2.

Best value

Within a category or a goal, a peptide that no other beats on both counts: none is rated more positively for the same or a lower monthly price, and none costs less for the same or a higher rating. The chart joins these into the best-value line; the cheapest of them and the best-rated of them both make it, so the line spans the trade-off from cheap to best. Avoid entries never count, and a peptide needs both a % positive and a price to be compared.

Testing

Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.

Added peptide

Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.