The finest fungus killer ever made has an F.D.A. approved ingredient Miconazole Nitrate, tested by the F.D.A. as an ingredient that kills fungus. Usually fungus grows in between the finger and the nail. To treat your infection, simply place a drop behind the nail and in between the nail and finger, put a drop on cuticle area as well. Do not apply on top of the nail. The fungus killer will not penetrate through the nail. It can not get to the root of the fungus where it is growing, living, & breathing. It can cause you to lose your nails. it can get out of control but before it does KILL IT! Take action against it!