ZnPaC is a supplementation protocol, taken for up to 10 days, built around four ingredients with published clinical evidence supporting potential benefit during a viral upper respiratory infection. Designed by a physician. Taken by that same physician. Honest about what it can and cannot do.
Get ZnPaC →Every year, millions of antibiotic prescriptions are written for viral upper respiratory infections — colds, sinus infections, bronchitis — that antibiotics cannot treat. The science has been clear on this for decades. The prescribing hasn't changed.
That is not entirely anyone's fault. Patients arrive expecting a prescription. Physicians are working inside a system that made the prescription pad the path of least resistance. The result is a cycle that harms patients, accelerates antibiotic resistance, and leaves everyone — patient and physician alike — with a problem that keeps coming back.
ZnPaC exists to interrupt that cycle. Not with a promise. With a plan.
I spent nearly fifteen years in urgent care watching the same scene play out, thousands of times.
A patient walks in feeling terrible. They're scared — not always about the severity of what they have, but about what it might become, about whether something is being missed, about why they still feel this bad. And they're suffering. Genuinely, miserably suffering. Congested, exhausted, behind on everything, not sleeping. They want someone to tell them it's going to be okay. And they want something to do about it.
What they usually left with was an antibiotic.
Not because the antibiotic would help them. For a viral upper respiratory infection — which is what the vast majority of these patients had — antibiotics have no demonstrated benefit. The science has been unambiguous on this for decades. What antibiotics do, reliably, is give patients something to take home. A plan. A prescription that feels like action. And that prescription, paired with natural recovery that was coming regardless, produced a belief that has proven almost impossible to dislodge: the antibiotic worked.
It didn't. But the plan did something. That part was real.
I thought about that for years. There's real value in having a plan when you're sick, acting with intention may itself be part of what helps you feel better. Patients who have a plan recover differently than patients who don't. Not because the plan is magic. Because agency changes the experience of illness. Feeling like you are doing something — the right something, the physician-endorsed something — reduces fear, reduces the sense of helplessness, and likely influences how the immune response unfolds.
The antibiotic was filling that need. It just happened to be the wrong tool for the job — one with real risks, no viral benefit, and a downstream cost that belongs to all of us.
What I wanted — what I needed — for fifteen years standing in that exam room, was something I could hand a patient that filled the same psychological need with a tool that actually made clinical sense. And eventually I stopped waiting for someone else to build it.
ZnPaC is four ingredients — Zinc, Quercetin Phytosome, NAC, and Vitamin C — each with published clinical evidence supporting potential benefit during a viral URI. I cannot promise you it will shorten your cold. The evidence doesn't yet allow that claim — not because the ingredients lack support, but because no one has funded the trial that tests this exact stack. Each ingredient has published evidence behind it. The combination has not been studied as a whole. What I can tell you is this: these four ingredients — this plan — represent the best clinical advice I can give you for what you are actually trying to do.
That is my clinical judgment. It is not a guarantee. It is what I believe — and it is what I take.
— Russell W. Raskin, MD
You feel sick. You don't know when you're going to feel better. You've been here before — and you know how it tends to go. You saw a doctor, you got an antibiotic, and at some point you got better. It worked. You need it again.
That reasoning is logical. It is also, almost certainly, wrong — and the way it became so convincing is worth understanding.
Viral upper respiratory infections follow a predictable arc. Symptoms escalate, plateau, and then resolve. Patients seek care at different points along that arc — some early, out of fear, some later, out of exhaustion with the suffering. Wherever you are when you walk in, the pattern that follows tends to be the same: antibiotic prescribed, improvement follows, antibiotic gets the credit.
What actually happened is that your immune system was doing its job. The antibiotic was the passenger. Your body was the driver. That experience — sick, antibiotic, better — repeated enough times, becomes a belief. A reasonable belief, built on real experience, that happens to have the cause and effect reversed.
Understanding this is not just an intellectual exercise. It changes what you reach for the next time you feel it coming on.
The full mechanism — including why this belief is so hard to dislodge — is explained in The Antibiotic Belief Cycle →
This is not a story about bad doctors. It is a story about a system that made the prescription the path of least resistance — and kept it there long after the science moved on. Billing structures, liability culture, time constraints, patient satisfaction scores, and a belief cycle that physicians are not immune to themselves. Good people, navigating a system that was never designed to make this easy.
We know better now.
The full story — seven forces, the history, the data — is in A Look Behind the Curtain →
Four ingredients. Each chosen for the same reason: published clinical evidence supporting potential benefit during a viral URI, and a safety profile that makes the decision easy. This is not a kitchen-sink formula. Every ingredient earned its place. The amounts below are the full daily dose, taken as two tablets.
Zinc is the anchor of this stack — and the ingredient with the most substantial acute evidence behind it.
Zinc has been studied in multiple clinical trials and may shorten cold duration by roughly one to two and a half days, particularly when taken close to symptom onset, though researchers note the science in this area isn't fully settled.1 The evidence favors early initiation — which is one of the reasons we recommend keeping ZnPaC on your shelf before you need it. That said, if you are already mid-illness, do not wait. Zinc plays a direct role in immune cell function throughout the course of an infection. Whenever you start it, start it.
You may have seen zinc delivered as lozenges and wondered why we chose an oral supplement instead. The lozenge theory holds that zinc ions released during dissolution in the throat create localized antiviral activity at the site of initial viral entry. That mechanism may have theoretical merit — but only as a prevention argument, and only before the virus has established itself. The moment you are symptomatic, that window is closed. The virus is already inside cells. It is already replicating. Your immune system is already engaged. Local zinc delivery to the throat mucosa at that stage is unlikely to matter — the battle has moved inside.
My postulate is simple: the benefit was from the zinc itself. Not the location. What matters is getting zinc to the cells where the immune response is happening — and a highly bioavailable oral form does exactly that. Once absorbed, it gets where it needs to go.
At 30 mg elemental, the dose is therapeutic for the acute protocol without approaching the threshold where long-term use creates concern. ZnPaC is a short course, taken for up to 10 days. That is by design.
Quercetin is the most intriguing ingredient in this stack — and the most misrepresented one in the supplement market. The truth about it is more compelling than most of what you will read elsewhere, and more complicated than any marketing claim will tell you.
The laboratory evidence for quercetin's antiviral activity is substantial. In vitro, it is believed to act against rhinovirus, influenza, RSV, and SARS-CoV-2 through multiple mechanisms — including interference with viral entry and replication, and suppression of the inflammatory response that makes you feel as terrible as you do.2
The clinical evidence is where it gets complicated — and where formulation becomes everything.
Standard quercetin — the form used in most supplements — has not shown a significant overall benefit for respiratory illness in a large general-population trial.3 That result is not surprising. You cannot benefit from an ingredient that does not reach its target.
Quercetin Phytosome — the specific form used in ZnPaC — achieves approximately twenty times the plasma levels of standard quercetin.4 That difference is not incidental. It is the entire argument. In one small clinical trial, participants taking Quercetin Phytosome also cleared the virus and recovered faster than those on standard care alone, though the study was limited in size and design.5 Formulation was the variable. Formulation was the result.
There is one more reason quercetin is in this stack — and it has to do with zinc.
Quercetin's primary role in this formula is as a zinc ionophore, helping shuttle zinc into cells where it may support the body's response to viral illness.6 Zinc needs a door. Quercetin helps open it. Vitamin C, also in this stack, may help regenerate oxidized quercetin back to its active form.7 These three ingredients are not simply coexisting in a capsule. They are working together.
That synergy has not yet been validated in a clinical trial — and I want to be honest about that. Closing that evidence gap is a goal of this platform. The trial I want to see does not yet exist. We intend to change that.
Until then, this is the best clinical answer I have. I believe in it enough to take it myself. I believe in it enough to put my name on it.
NAC is the ingredient in this stack that most patients have never heard of. It is also the one with the single most striking clinical finding.
In a landmark trial, people taking NAC during peak cold and respiratory illness season experienced far fewer symptomatic illnesses than those on placebo, a difference researchers called dramatic.8
That is a remarkable finding. It has not yet been replicated at scale in a younger general population, and I will not overstate what one trial proves. But the mechanism behind it is well understood — and it is directly relevant to what happens during a viral URI.
NAC is a precursor to glutathione, the body's most important endogenous antioxidant. During a viral infection, oxidative stress rises sharply as the immune response mounts. Glutathione is depleted in the process. NAC replenishes the substrate the body needs to rebuild it — supporting the immune response at precisely the moment it is under the most demand.9
NAC is also a mucolytic. It breaks down the disulfide bonds in mucus, reducing viscosity and helping clear the congestion that makes a viral URI so miserable.10 This is not a secondary benefit. If you have ever been flattened by congestion that will not move, you understand exactly why this matters.
Vitamin C is the ingredient everyone thinks they already understand.
The evidence around vitamin C and respiratory illness is more nuanced than most people realize. Vitamin C may offer a modest reduction in cold duration when taken during active illness.11 Its role in preventing colds before they start is not well supported by current evidence.
We include it here for two reasons.
The first is that modest direct benefit, combined with a near-zero risk profile. That clears the bar.
The second is what it does for the rest of the stack. Vitamin C may also help regenerate oxidized quercetin back to its active form7 — one more reason these ingredients were chosen to work together rather than in isolation.
Four ingredients. One protocol. That is ZnPaC.
How to take it.
ZnPaC is built to cover the full arc of a typical cold, which usually runs about a week to ten days. Take 2 tablets daily. Always take them with food and a beverage, never on an empty stomach. A lower-sugar orange juice cut with seltzer is my cocktail. You can take the two together, or split them one in the morning and one at night, whatever is easier for you.
It may be taken for up to 10 days. Start as soon as you realize you're getting sick. Earlier is better, but there's still a role for it wherever you begin. Keep a pack on hand so it's there the moment you need it.
Zinc does its most useful work early, in the first day or so of symptoms. That is the whole case for starting at the first tickle, and for keeping a sealed pack on hand so you can. The later days of the course are carried by the other components.
Later in a cold, what lingers is usually cough and mucus, and some of the stack may still have a supporting role. The main reason the course can run this long is simpler: there is little downside to continuing, and you stop as soon as you are clearly better.
The pack holds 20 tablets in two blister packs of 10, a course that may be taken for up to 10 days.
ZnPaC includes 500 mg of vitamin C to support normal immune function. We don't build the product around a mega-dose of C. Leading with grams of vitamin C is marketing, not medicine, and it's a place we're deliberately different.
What ZnPaC is — and what it isn't.
ZnPaC is a supplementation protocol, taken for up to 10 days, designed for use during a viral upper respiratory infection. It is not a cure. It is not a replacement for medical care when medical care is genuinely needed. It will not treat a bacterial infection, and it is not designed to.
What it is: the best clinical answer currently available when a viral URI sets in — whether you catch it early or you're already days in. Four ingredients with published evidence behind them, a defined protocol with a clear endpoint, and a physician who believes in it enough to take it himself.
If your symptoms are worsening significantly, if you develop high fever, shortness of breath, chest pain, or anything that feels different from a cold — seek care.
If you're not improving by the end of the pack, if you'd started feeling better and then relapsed, or if anything on our When to Seek Care page fits, that's not a reason to keep taking ZnPaC. That's a reason to get seen.
You don't have to finish the pack. Once you've felt clearly better for a few days, you may stop.
This platform, used properly, will likely lead to fewer unnecessary physician visits. I want to be direct about that — because it is a double-edged sword and I am aware of it. Reducing visits affects revenue for urgent care operators. I am an urgent care operator.
I built it anyway.
The patient who understands they have a viral URI does not need to be seen on day three. The patient with worsening symptoms, high fever, or something that feels different absolutely does. This platform tells you both. That is part of what makes it something you can trust rather than something that is simply trying to sell you something.
ZnPaC is a product I designed, take myself, and sell. I have a financial interest in it. I am telling you that directly because you deserve to know it — and because the case for this product does not require me to hide it. The evidence is what it is. My clinical judgment is what it is. My name is on this platform and my integrity is on this product.
That has always been non-negotiable. It always will be.
— Russell W. Raskin, MD