Toenail fungus is notoriously hard to cure. Both oral and OTC anti-fungal medications take time to reach the fungus under the nail where it lives. Also, once the medication kills the fungus, it won’t improve the look of the infected nail right away. As the new, healed nail grows out, the thick, discolored nail is trimmed away. It may take 6-9 months for the new nail to grow all the way out.