Written by the Nail Health Guide Editorial Team Reviewed under the editorial direction of Laura Collins, Editorial Lead.
Quick Summary: Kerafen is a topical antifungal oil built around 15 natural ingredients, led by undecylenic acid — an FDA-recognized topical antifungal — and a blend of essential and carrier oils including tea tree, camphor, clove bud, and lavender. Here’s what each ingredient actually does, and where the marketing claims outpace the evidence.
For our full product breakdown, see the Kerafen Review.
Before applying any topical treatment to your skin or nails, it’s worth understanding exactly what’s in it — not just the marketing description, but what each ingredient is actually known for. Here’s our ingredient-by-ingredient breakdown of Kerafen.
The Full Ingredient List
Kerafen’s topical oil formula includes:
- Undecylenic Acid
- Tea Tree Essential Oil (Melaleuca Alternifolia)
- Camphor Oil (Cinnamomum Camphora)
- Jojoba Oil (Simmondsia Chinensis)
- Clove Bud Essential Oil (Syzygium Aromaticum)
- Chia Oil (Salvia Hispanica)
- Manuka Oil (Leptospermum Scoparium)
- Lemongrass Oil (Cymbopogon)
- Lavender 40/42 Essential Oil
- Organic Flaxseed Oil
- Aloe Vera
- Vitamin E
- Sweet Almond Oil
- Menthol
- Walnut Oil
According to manufacturer claims, it’s produced in an FDA-registered, GMP-certified US facility.
Ingredient-by-Ingredient Breakdown
Undecylenic Acid — The Primary Active Ingredient
This is the ingredient that matters most. Undecylenic acid is a fatty acid, commonly derived from castor oil, and is one of the few natural-origin antifungal compounds recognized as an over-the-counter antifungal active ingredient. It’s used in various nail and skin antifungal products beyond just this one — it’s a genuinely established compound, not a novel or unproven one.
Tea Tree Essential Oil
Contains terpinen-4-ol, one of the most studied natural compounds for antifungal activity against dermatophytes (the fungus family responsible for most nail infections). Widely used across natural antifungal formulations, not unique to Kerafen.
Camphor Oil
Traditionally valued for its cooling sensation and mild antimicrobial associations. Also commonly used in topical products for muscle and joint discomfort — its inclusion here likely serves both a sensory (cooling) and mild antimicrobial supporting role.
Jojoba Oil
A carrier oil, chemically closer to a wax ester than a true oil, commonly used in skincare for its moisturizing properties and its ability to help other ingredients spread evenly and absorb into skin and nail tissue.
Clove Bud Essential Oil
Contains eugenol, a compound found in various studies to have antifungal and analgesic (pain-relieving) properties. Also contributes to the formula’s strong scent.
Chia Oil
Rich in omega-3 fatty acids. Primarily a conditioning ingredient here, supporting nail and skin moisture rather than acting as a primary antifungal agent.
Manuka Oil
An essential oil native to New Zealand, in the same botanical family as tea tree oil, with broadly similar antimicrobial associations.
Lemongrass Oil
Contains citral, a compound that has been studied for antifungal properties in various essential oil research contexts, though less extensively than tea tree oil.
Lavender 40/42 Essential Oil
Primarily included for its anti-inflammatory and calming properties — helps reduce redness and irritation around the nail bed, particularly relevant given how many other essential oils are in this formula.
Organic Flaxseed Oil
An omega-3-rich carrier oil, supporting skin conditioning and helping with the overall texture and absorption of the formula.
Aloe Vera
A well-established skin-soothing ingredient, helps calm irritation from the concentration of essential oils in the rest of the formula.
Vitamin E
An antioxidant that supports skin and nail moisture, and helps protect against oxidative stress in the surrounding tissue.
Sweet Almond Oil
A conditioning carrier oil. Note: relevant for anyone with a tree nut allergy.
Menthol
Provides the cooling sensation noticeable immediately after application. Primarily a sensory ingredient rather than an antifungal one.
Walnut Oil
Another conditioning carrier oil. Note: also relevant for anyone with a tree nut allergy, alongside almond oil.
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The Pattern Worth Noticing
Of the 15 ingredients, only a handful have a well-established, direct antifungal association: undecylenic acid (the strongest), tea tree oil, manuka oil, clove bud oil, and lemongrass oil to a lesser extent. The remaining ingredients — jojoba, chia, flaxseed, almond, walnut, aloe vera, vitamin E, and menthol — serve conditioning, soothing, or sensory roles rather than direct antifungal ones.
This is a fairly typical composition for products in this category: one or two genuinely active antifungal ingredients, supported by a larger blend of conditioning and sensory oils. It doesn’t mean the supporting ingredients are useless — nail and skin conditioning does matter for overall treatment comfort and consistency — but it’s worth knowing which ingredients are doing the antifungal work and which are there for texture, scent, and comfort.
About the “Biofilm-Disrupting” Claim
Kerafen’s marketing associates several ingredients (particularly camphor, jojoba, chia, and clove) with disrupting the protective “biofilm” that nail fungus can form. The general concept — that microbial biofilms increase resistance to treatment — is a real, studied phenomenon in microbiology. However, the specific claim that this exact blend of oils disrupts fungal biofilm on nails hasn’t been independently tested for this finished formula, as far as we could verify. Treat this as a reasonable-sounding marketing narrative built on real science, not as an independently proven mechanism for this product.
Allergy and Sensitivity Considerations
| Ingredient | Consideration |
|---|---|
| Sweet Almond Oil | Tree nut allergy risk |
| Walnut Oil | Tree nut allergy risk |
| Clove Bud Oil | Can cause skin sensitivity in concentrated form |
| Camphor Oil | Can cause skin sensitivity, especially in children or sensitive skin |
| Lavender, Tea Tree, Manuka, Lemongrass | Standard essential oil sensitivity risk — patch test recommended |
A patch test on a small area of skin 24 hours before full application is a reasonable precaution given how many essential oils are concentrated in this formula.
👉 For the complete safety picture, see our Kerafen Side Effects guide.
Frequently Asked Questions
What is the main active ingredient in Kerafen? Undecylenic acid — an FDA-recognized topical antifungal fatty acid. It’s the ingredient with the strongest, most established antifungal evidence in the formula.
Does Kerafen contain any allergens? Yes — sweet almond oil and walnut oil are both present, which is relevant for anyone with a tree nut allergy.
Are all 15 ingredients antifungal? No. Only a handful (undecylenic acid, tea tree oil, manuka oil, clove bud oil, and to a lesser extent lemongrass oil) have a direct antifungal association. The rest serve conditioning, soothing, or sensory roles.
Does the “biofilm” claim hold up? The general biofilm concept is real microbiology, but the specific claim that this formula disrupts biofilm on nail fungus hasn’t been independently verified for the finished product. Treat it as marketing built on real science, not a proven mechanism.
Is Kerafen’s ingredient list safe? Generally yes for most people, with the caveats above regarding tree nut allergies and essential oil sensitivity. A patch test is a reasonable precaution.
⚠️ Medical Disclaimer
This content is for informational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional before starting any new treatment, especially if you have known allergies or sensitive skin.
Continue reading:
- 👉 Full Kerafen Review
- 👉 Kerafen Scam or Legit?
- 👉 Kerafen Side Effects: Is It Safe?
- 👉 Where to Buy Kerafen
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Reviewed by Laura Collins — Editorial Lead at Nail Health Guide. Learn more about Laura Collins