I've had fungus in my toe nails for the last 4 years. What is the most effective treatment?

We can try! Toenail fungus is very common, and unfortunately very difficult to cure 100%. We can test the nail to see if it is a callused or traumatized nail or if it is indeed fungus, and from there you have several options: topical or oral antifungal medications, laser nail treatment, or removal of the nail in severe cases. See your doctor to talk about which treatment is right for you.
Oral antifungals. The most effective treatment for onchomycosis is oral antifungals (i.e., terbinafine) taken for 12 weeks. Because of potential adverse effects on the liver, it is recommended to check liver function tests while on this therapy.