Tea tree oil can be used to treat fungal nail infections, WebMD advises. However, tea tree oil only fully cures nail fungus about 18% of the time.
A topical solution made of 100% tea tree oil applied to the nails twice daily is only effective in 18% of people who tried it, WebMD elaborates. Most people -- about 56% noticed improvement in nail appearance after three months of tea tree oil treatment. However, weaker solutions of the oil do not produce the same effect. WebMD states at a 5% concentration of tea tree oil used over three months has no benefit to the patient. The results tea tree oil illicit are similar to over-the-counter anti-fungal medicines, such as Fungoid or Lotrimin.