Treat the fungus behind it
25% undecylenic acid treats most athlete’s foot on the skin, including affected areas between the toes.
Itchy, burning feet?
Give the cause your attention.
Help calm the symptoms you feel
Relief for the itching, burning and scaling that can make your feet hard to ignore.
Know what you’re treating
Athlete’s foot affects the skin. An infection inside or underneath the nail needs a different treatment.
25% undecylenic acidMax-strength athlete’s foot treatment
Antifungal Pen
Done with greasy creams and powder that ends up everywhere? Brush 25% undecylenic acid, the maximum strength FDA rules allow for this antifungal, right onto the itchy, peeling skin between your toes. Treats most athlete’s foot and relieves the itching, burning and scaling.
- Treats most athlete’s foot
- Relieves itching & burning
- Helps relieve scaling & irritation
- Brush directly onto affected skin
For athlete’s foot on the skin, including affected skin between the toes. For external use only. Does not treat infection inside or underneath the toenail.
About the antifungal pen+
Athlete’s foot shouldn’t run your day.
The itch between your toes. The burning inside your shoes. The flaky skin you would rather keep covered. Nutralab brings targeted treatment to the skin that needs it, helping you work toward more comfortable feet.
With 25% undecylenic acid, the Antifungal Pen treats most athlete’s foot and helps relieve its associated itching, burning, scaling and irritation.
- Treats most athlete’s foot on the skin
- Helps relieve itching, burning and scaling
- Precision brush for direct application, including between the toes
- Available in 1-, 3- and 6-pen packs
Make treatment part of your routine
Clean the affected area, dry thoroughly and brush on a thin layer as directed on the label. Follow the full treatment course, even if discomfort eases earlier.
For external skin use only. Does not treat infection inside or underneath the toenail. Avoid the eyes. Stop use if irritation occurs and consult a healthcare professional if there is no improvement within 4 weeks or as directed on your label. Ask a healthcare professional before self-treating a foot problem if you have diabetes or poor circulation.
Active ingredient & botanicals+
Active: Undecylenic acid 25%.
Key supporting ingredients: Tea tree oil, oregano oil, manuka oil, clove bud oil, propolis extract, and vitamin E.
Read the product label for the complete ingredient list and warnings.
How to use+
Wash the affected skin and dry thoroughly, especially between your toes. Brush a thin layer onto affected skin, following the frequency and full treatment period on your product label. Avoid contact with the eyes. Stop use if irritation occurs; consult a healthcare professional if there is no improvement within 4 weeks or as directed on your label.
Shipping & returns+
Shipping options and charges appear at checkout. Review our shipping and return policies for processing, delivery, and eligibility details.
Shipping policyReturn policyFour steps. No mess. No guesswork.
Clear directions are half the battle. Here’s exactly what to do, from the first application to the last.
Know the concern
Itchy, scaly skin between the toes can be athlete’s foot. If you’re unsure what’s causing it, ask a pharmacist or healthcare professional.
Wash. Dry thoroughly.
Clean the affected skin and dry it carefully, including between the toes, before applying treatment.
Brush onto affected skin
Apply a thin layer using the brush. Follow your product label for how often to apply it.
Follow the full course
Keep going for the full labeled treatment period. Stop if irritation occurs, and seek advice if the condition is not improving.
Max-strength antifungal.Precision delivery.
Go after the fungus, not just the itch
Undecylenic acid 25%
The maximum strength FDA rules allow for this antifungal.
Athlete’s foot is a fungal skin infection, so masking the smell or drying the sweat on its own won’t treat it. Undecylenic acid is an FDA-recognized antifungal active, and Nutralab uses it at 25%, the top of the allowed range, in a formula you brush straight onto affected skin. Use as directed.
25%Antifungal active
Skin between the toes
Targeted brush application
Before & after
From peeling, burning toes back to comfortable feet.
Red, cracked, peeling skin between your toes is the fungus at work. Left alone, athlete’s foot tends to hang around, and it can spread to your toenails or hands.
Brush 25% undecylenic acid onto that skin as directed, every day for the full course, even after the itch fades, and give your feet the chance to get back to normal.
Drag the slider to compare. Results vary; use as directed. Also contains tea tree, oregano, manuka and clove bud oils, propolis and vitamin E. Check the full label if you’re sensitive to botanical oils or bee-derived ingredients.
Less distraction. More everyday comfort.
Your feet deserve care that’s focused on what’s getting in your way.
When my feet itch, it’s hard to think about anything else. What I want is straightforward care I can make part of my routine, so my day isn’t built around the discomfort.
I want to sit down after a busy day and actually relax. Taking care of the itchy skin on my feet is something I’d like to stop putting off.
I’m looking for care that focuses on the affected skin. Being able to see where I’m applying it, and follow a clear routine, matters to me.
It’s the little things I miss—wearing my usual shoes and getting on with my plans. That’s the comfort I want my foot-care routine to work toward.
Dry, flaky skin can make me feel self-conscious. I want to give my feet consistent care instead of covering them up and hoping the problem goes away.
I’m looking for a simple way to care for irritated skin, with instructions I can understand. I want to know what the product is for and how to use it.
I’d like to feel more comfortable looking after my feet. A focused routine feels more manageable to me than adding several different steps.
I want to stop ignoring those uncomfortable patches of skin. For me, the first step is finding the right care for the concern I actually have.
I want to enjoy a walk, time in the garden, or an afternoon out without my feet always being on my mind. Everyday comfort is the reason I’m looking for care.
My goal is to feel more at ease in my usual routine. I want foot care that’s clear enough to follow consistently, even on a busy day.
I want to feel comfortable in the shoes I choose and confident getting on with my plans. Those ordinary moments matter more to me than a complicated routine.
Being able to focus on family, hobbies, and the day ahead is what I’m working toward. I want my foot-care routine to fit into that life.
No reviews in this category yet.
Know what to expect before you start
Your athlete’s foot questions, answered.
Straight answers about treatment, symptoms and getting your routine right.
Contact our teamI’ve already tried creams and sprays. Why would this be different?+
Fair question, and we won’t promise a miracle. What’s different is the combination: 25% undecylenic acid, the maximum strength FDA rules allow for this antifungal, delivered by a precision brush straight onto affected skin, without the greasy fingers or powder mess that make treatment easy to abandon. Use it as directed for the full course, even after the itch fades. If you’re not happy, you’re covered by our 30-Day Guarantee.
Do vinegar, bleach or other home soaks work?+
They’re popular online, but vinegar, bleach, mouthwash and baking-soda soaks are not approved athlete’s foot treatments, and harsh soaks can sting and dry out skin that’s already irritated. Bleach in particular can burn skin. For athlete’s foot, use our antifungal pen as directed on its label.
Will this help with athlete’s foot?+
Nutralab contains 25% undecylenic acid to treat athlete’s foot and help relieve its associated itching, burning, scaling and irritation. Apply only to the skin and areas listed on your product label, and follow the directions through the full course.
Will it treat fungus inside my toenails?+
No. The pen treats fungal infection on the skin. It does not treat infection inside or underneath the toenail. Thickened, discolored or brittle nails may need a different treatment; a healthcare professional can help identify the problem.
How do I use it for athlete’s foot?+
Wash the affected skin and dry it thoroughly, especially between the toes. Brush on a thin layer as directed on your product label. Follow the label for application frequency and the full treatment period. For external use only; avoid contact with the eyes.
How soon should I expect a difference?+
Treatment takes time, and response varies. Follow the complete course on your label, even if symptoms ease earlier. Stop use if irritation develops. If there is no improvement within 4 weeks, or your label advises sooner, consult a healthcare professional.
What is the active ingredient?+
The active ingredient is undecylenic acid 25%. The formula also contains tea tree, oregano, manuka and clove bud oils, propolis extract and vitamin E. Read your product label for the complete ingredient list and warnings.
Can I use it if I have diabetes?+
Speak with your healthcare professional before treating a foot concern yourself if you have diabetes.
What if my skin is sensitive?+
Check the complete ingredient list before use, especially if you react to botanical oils or bee-derived ingredients such as propolis. Follow the label’s warnings. Stop use if the product irritates your skin.
Should I choose 1, 3 or 6 pens?+
Choose the quantity that suits your needs. The larger packs lower the price per pen compared with buying single pens separately.
Where can I check shipping and returns?+
Available shipping options and charges appear at checkout. Our shipping and return policies explain delivery information, return eligibility and how to get help with an order.
Can athlete’s foot come back?+
Yes, athlete’s foot can recur. Alongside treatment, dry carefully between your toes, wear fresh socks, let shoes dry between wears, and avoid sharing towels or footwear. These habits support foot hygiene.
Max-strength 25% undecylenic acid
Precision brush reaches between toes
No greasy fingers. No powder mess.
Why people switch to the pen.
| Feature | Nutralab Pen |
 Creams, sprays & powders |
|---|---|---|
| Treats most athlete’s foot | ||
| Max-strength 25% undecylenic acid | ||
| Precision brush for between the toes | ||
| No greasy fingers, no powder mess | ||
| Pocket-size, twist-to-dispense |
Compares the format and application features of typical over-the-counter creams, sprays and powders, not clinical results. Many contain effective antifungal actives; always follow each product’s label. For athlete’s foot on the skin, not infection inside the nail.
You’ve tried the rest
Ready to treat athlete’s foot the precise way?
Choose your pen pack, brush it on as directed, and give your feet max-strength treatment you can aim. Backed by our 30-Day Guarantee.
Get the Antifungal Pen