The Clearnail Protocol

Honestly? The pen alone isn’t the whole answer, and we’re not going to pretend it is.

Most people who try a brush-on pen apply it to a thick, intact nail and watch nothing happen for two months. That’s not the pen’s fault. The visible nail is dead keratin, and the fungus lives underneath it in the nail bed. Anything brushed onto the surface of a thick nail rarely reaches the fungus in any meaningful concentration.

The Clearnail Protocol is built around the step everyone else leaves out: thinning the nail first with the included file so the 25% undecylenic acid actually has a path to where it needs to go. The kit comes with everything required to do that properly, the file built for thick nails, the medical-grade nipper, the prep pads to disinfect tools, and the patches to hold treatment in place overnight. That’s the difference. Same kind of active ingredient most pens use. Completely different method.

We’ll be straight with you on this because being unrealistic here is what makes people give up too early.

Toenails grow about 1 millimeter per month. The first sign that the protocol is working isn’t the whole nail clearing, it’s a thin band of healthy, clear new nail appearing at the base, usually around week 4 to 6 of consistent use. That band widens every month as new growth pushes the damaged nail out, which you trim away at the top.

A full nail-growth cycle on a great toenail is typically 9 to 12 months. Smaller nails clear faster, often 4 to 6 months. Consistency beats intensity every time. Twice a day, every day, for one full cycle.

You get your money back. Plainly.

We offer a 60-day money-back guarantee. If you follow the protocol consistently and don’t see a clear band of new nail growing in at the base by the end of 60 days, email us and we’ll refund your order.

One honest note: we ask that you actually follow the protocol, twice daily, with the filing step. Most refund requests we see come from people who tried it for two weeks and quit. That’s not the protocol failing, it’s stopping before the timeline can show anything. But if you follow it through and it isn’t working for you, we’ll make it right. No paperwork hoops, no “you have to ship the empty bottle back.”

You can. And plenty of people do, then end up right back where they started. We’d rather tell you why up front than have you find out the hard way.

The pen isn’t usually the part that goes wrong when people DIY this. The file is. Most files sold individually are soft cosmetic emery boards meant for smoothing a healthy fingernail. They don’t thin a hardened, fungal toenail. That means the most important step in the protocol, reducing the barrier, never actually happens. You’ll file the surface for a minute, feel like you did something, and the dead nail is still a thick locked door.

Then there’s what doesn’t make it into the cart at all: clippers strong enough for a brittle nail, alcohol pads to disinfect tools (which is how people quietly re-seed the fungus into healthy nails), and the patches to hold treatment in place overnight.

The kit is priced the way it is because it’s a method in one box, with the right tools sized to the job and nothing missing. Not four random items with no instructions.

Here’s the honest framing.

Undecylenic acid is recognized in the FDA over-the-counter monograph as an antifungal active for skin (athlete’s foot, ringworm, jock itch). Nails are biologically harder to treat than skin because of the keratin barrier we’ve been talking about throughout this page, which is exactly why the filing step in our protocol matters: it gives the active ingredient access it wouldn’t otherwise have.

For mild to moderate cases, this kind of topical-plus-debridement approach is genuinely effective when followed consistently through a full nail-growth cycle. For severe cases (matrix involvement, extensive nail destruction, lots of nails affected), oral prescription antifungals are stronger. Your podiatrist can help you decide where you sit on that spectrum.

The full routine takes about five minutes, morning and evening. Five steps:

• Cleanse the nail with an alcohol prep pad and let it dry.
• Trim any loose or lifted edge of the nail back with the nipper.
• File the surface gently with the 100-grit side once or twice a week (not daily) to thin the nail.
• Treat by brushing the 25% undecylenic acid pen across the nail, into the edges, and under the front lip. Twice a day.
• Protect with a patch over the nail at bedtime to keep the treatment in contact overnight.

Every kit ships with a printed step-by-step guide that walks you through it in more detail, including a day-by-day tracker so you can build the habit.

This is one of the most common fears we hear, and it’s a legitimate one. The good news is it’s also manageable.

Toenail fungus does spread, most commonly through contact with infected nail tools, towels, shower floors, and shoes. The alcohol prep pads in the kit are included specifically for this reason: wipe the file and nipper after every single use, every time. That’s the step that keeps you from re-seeding the fungus into your healthy nails or anyone else’s.

Also worth doing alongside the protocol: don’t share nail tools, wear sandals in shared showers or pool areas, alternate shoes so each pair fully dries between wears, and wash socks on the warmest setting your fabric allows. Boring, but it’s what prevents reinfection.

Topical undecylenic acid is generally well tolerated. The most common reactions are mild and local: temporary stinging on broken skin, dryness, or mild irritation at the application site. Stop using it if irritation persists.

Because this is a topical, you don’t have the systemic liver-related concerns that come with oral antifungal pills. That’s a meaningful difference for a lot of people.

Please see a doctor before using any at-home treatment if you have diabetes, peripheral neuropathy, poor circulation, or a compromised immune system; if the nail is painful or the surrounding skin is red, swollen, or weeping; or if you’re pregnant or nursing. This product is for external use only, on intact skin and nails.

It depends, and we’d rather be honest than just say yes.

For people with multiple affected nails and significant thickening but no pain, no skin involvement, and no underlying health concerns, the protocol can still work, it just takes longer and your file step matters more than usual. Each nail needs to be thinned consistently before applications, and you may need a second kit to make it through the full cycle on multiple nails.

For severe cases where the nail is mostly destroyed, the matrix (the base where the new nail is generated) is involved, or several nails on multiple feet are affected, oral prescription antifungal therapy is often the more appropriate first-line approach. Your podiatrist can assess and help you decide. We’d rather lose your sale today and have you come back later than sell you something that wasn’t the right tool for your situation.

Not during active treatment.

Polish is occlusive, it traps moisture against the nail, which is exactly the environment fungus loves. It also blocks your treatment from penetrating and makes it impossible to see the clean band growing in at the base, which is your single most important progress indicator.

Once your nail has fully cleared and grown out and you’ve completed maintenance for a few weeks, occasional breathable polish is fine. During treatment, give the nail a break.

The kit is designed to last roughly 3 months of twice-daily use on a few nails, four pens at 3 mL each, plus 32 patches and 100 prep pads.

If you’re treating multiple toenails, you’ll go through it faster. If you’re treating one nail with mild involvement, you’ll have leftovers. For most people working through a full nail-growth cycle on a big toenail, plan on needing two kits total to make it all the way to clear new growth.

Orders ship from the U.S. within 1 business day of being placed, and standard delivery typically arrives in 3 to 5 business days from order date. You’ll get a tracking number by email as soon as it’s on its way.

Yes, the box is discreet. The outer mailer doesn’t say “fungus” on it anywhere, just a plain shipping label with our company name. We know this isn’t something most people want their roommate or partner reading off a delivery.