VIP Deep Dive

Happy Tuesday!

Two weeks ago, I wrote an email about the many benefits of VIP.

Today, I just launched my new VIP guide on Spotify.

I’ve done content on VIP in the past, but it was due for an update as we head into 2026.

Taylor and I were talking recently about peptide trends for 2026.

GLP peptides are obviously here to stay.

But what I hope becomes a trend is more attention to peptides that appear to have a single specific use case but, in reality, act as master regulators throughout the body.

VIP is absolutely one of those peptides.

Most people only think lungs or mold.

And yes, it’s incredible for those.

But that’s not the full story. VIP is a broad-spectrum regulator that touches vascular tone, immune balance, gut function, brain fog, circadian rhythm, mood, and autonomic stability.

And once you understand that, it becomes obvious why it has a use case for almost everyone.

How VIP Works

VIP stands for Vasoactive Intestinal Peptide.

It’s a 28–amino acid regulatory peptide that was first isolated back in 1970.

The name makes people think it’s just a gut peptide, but it’s not limited to the gut at all.

VIP is produced throughout the body with high concentrations in the brain, lungs, heart, intestinal tract, and endocrine organs, which already hints at why it’s so versatile.

Here’s the mechanism, and I’m going to keep it technical but practical.

VIP binds to receptors on cells called VPAC1 and VPAC2.

These are G-protein-coupled receptors spread all over the body. When VIP binds, it triggers cAMP signaling (cyclic AMP), which activates downstream pathways that change what your cells do.

In plain English, VIP tends to make three big categories of things happen:

That’s why I call VIP a Swiss Army knife peptide. Very few peptides hit those three categories at once.

Benefits

When you zoom out, VIP’s benefits fall into a few big buckets.

Pulmonary / breathing: VIP relaxes airway smooth muscle and supports bronchodilation, which is why so many people feel that “open chest / easier breathing” sensation when it hits right. It also influences pulmonary blood flow, which matters for oxygenation and exercise tolerance.

Vascular / endothelial health: VIP is a real vasodilator. When blood vessels open, endothelial function improves, circulation improves, and downstream effects show up in metabolic health, heart health, and even brain function. A lot of “mystery symptoms” people live with are actually vascular tone problems.

Immune regulation: This is massive. VIP helps suppress inflammatory cytokines and boosts anti-inflammatory signaling. It promotes immune balance and can shift the body out of a hypervigilant immune state that manifests as autoimmunity, chronic inflammation, and mast-cell/histamine patterns.

Brain / mood / circadian rhythm: VIP plays a role in synchronizing circadian rhythm. It influences areas of the brain tied to anxiety and mood regulation. In my experience, it has a calming effect that feels very stabilizing.

Gut: VIP improves GI motility and reduces spasm. For me, it noticeably improves stool quality and regularity.

Clinical Trials

There’s real human data on VIP across different categories.

Pulmonary arterial hypertension: Inhaled VIP has been studied in pulmonary hypertension protocols. The human data showed meaningful improvements in pulmonary pressures and functional outcomes, such as 6-minute walk distance.

ARDS / COVID respiratory failure: VIP (as aviptadil) was pushed into critical illness settings. Early case series looked promising, but larger randomized trials were mixed and didn’t show dramatic improvements across the board in long-term outcomes. Still, VIP was considered biologically relevant enough to trial in ICU-level inflammatory lung disease.

Mood/anxiety correlations: Observational human work has shown that higher circulating VIP levels correlate with lower anxiety/depression scores and differences in brain connectivity patterns associated with emotional regulation. Correlation isn’t causation, but it lines up with what many people feel subjectively.

CIRS / mold protocols: One of the most well-known uses of VIP clinically is in chronic inflammatory response syndrome (CIRS) related to mold exposure, often via intranasal VIP. Human clinical reports show improvements in quality of life and normalization of inflammatory markers in patients who were otherwise stuck.

Dosing

Most VIP comes as a 5 mg vial (sometimes 10 mg). My standard reconstitution for a 5 mg vial is:

With that dilution, dosing is extremely simple using a U-100 insulin syringe.

That’s it. Clean and repeatable.

Frequency-wise, you can run VIP 1 to 4 times per day depending on your use case. A very reasonable starting pattern is 50–100 mcg in the morning, then optionally another dose later in the day. I’ve personally gone up to around 150 mcg in a single dose.

VIP has a rapid onset. You’ll usually feel it within 5 minutes, it peaks around 15 minutes, and the “big sensations” are typically done within 30–45 minutes, even though the regulatory benefits can carry through the day.

Intranasal VIP is also great.

Intranasal tends to be milder systemically and can yield greater cognitive benefits for some people.

You can snag a 5mg bottle of VIP from BioLongevity Labs and get 15% off when you use code HUNTERW at checkout.

Final Thoughts

VIP is one of the most bang-for-buck peptides in the entire space because it improves the environment on which all your other interventions depend.

If VIP is a good fit for you, you can expect the following:

The first few times you use it, you’ll likely notice a niacin-like flush and warmth, sometimes a mild headache from vasodilation, and occasionally some GI urgency.

Those effects are usually transient and often diminish as you dial in dose and frequency.

VIP is a peptide you use to restore vascular tone, immune tone, nervous system tone, and gut tone.

And when the tone is right, everything else tends to work better.

Best,

Hunter Williams