Kerassentials Ingredients: What Research Says About Each One

By Nail Evidence Review Editorial Team · Updated 2026-11-09

A formula is only as credible as its evidence. This page looks at the Kerassentials ingredient list one component at a time. Only undecylenic acid has a stated strength, so findings on the other ingredients cannot be assumed to apply at the levels in the bottle.

The full Kerassentials ingredient list

A product label image lists: undecylenic acid USP (5%), mineral oil, sweet almond oil, organic flaxseed oil, tea tree oil, aloe vera leaf extract, canola oil, tocopheryl acetate (vitamin E), walnut oil, menthol, camphor oil, clove bud oil, jojoba oil, chia oil, lemongrass oil, lavender oil, and manuka oil.

The sales page highlights only eight of these and marketing images mention "6 natural oils," so compare the list with the label on the bottle you receive.

Tea tree oil

This is the ingredient with the most relevant research. In a double-blind trial of 117 people with culture-proven toenail infection, twice-daily 100% tea tree oil was compared with 1% clotrimazole for six months. Published summaries report a mycological cure of about 18% with tea tree oil and 11% with clotrimazole, and clinical improvement of about 60% in both groups.

Two limits matter. The trial used undiluted oil, while Kerassentials lists tea tree after mineral, almond, and flaxseed oils and states no percentage, so it is very likely far more dilute. There was also no placebo group. The American Academy of Dermatology says tea tree oil has only small studies so far. Redness and irritation occurred in a minority of trial participants.

Undecylenic acid

Listed first on the label at 5%, undecylenic acid is an established over-the-counter antifungal for skin infections such as athlete's foot. Nails are a different matter: OTC product labels for this ingredient carry the statement that it is not effective on the scalp or nails. Its presence in the formula may help the surrounding skin, but it is not evidence that the oil treats the nail itself.

Menthol and camphor

These give a cooling feel and a medicinal scent. The American Academy of Dermatology says mentholated ointments have only small studies so far. Both can irritate sensitive skin.

Lemongrass, lavender, clove bud, and manuka oils

These essential oils are studied mostly for general antimicrobial activity. We did not find a clinical trial of any of them in nail infection. A result in a lab dish does not show that an oil penetrates a thick toenail, and essential oils can cause skin sensitivity in some people.

Carrier oils, aloe vera, and vitamin E

Mineral, almond, flaxseed, canola, walnut, jojoba, and chia oils make up the base along with aloe vera and vitamin E. They may soften skin and improve how dry nails look, which can be a real cosmetic benefit, but moisturizing is not the same as clearing a fungus. People with a tree nut allergy should note the almond and walnut oils.

Safety checklist before using any essential oil blend

• Patch test on a small area of skin and wait 24 to 48 hours.
• Stop if you get redness, burning, or a rash.
• Keep it away from broken skin.
• Ask a clinician first if you are pregnant, nursing, on medication, or have diabetes.