According to the card, before each use the nail is cleaned and any polish removed; no prior filing is needed. During the first four weeks the solution is applied twice a day, after that once a day until the damaged nail is replaced by a healthy one. The solution is applied to the whole surface of the nail, including the area under the free edge; after application the feet are not washed for several hours and the pencil is closed tightly.
General information (not a manufacturer's instruction): the product is for external use only; avoid contact with the eyes and mucous membranes.