There is no data support for how long does terbinafine work for ten years of gray nails, so it is not possible to make an accurate judgment on this situation, which is generally related to the growth rate of diseased nails and so on. Gray nails that is nail fungus, is a common dermatological disease, refers to the skin fungus invasion of the nail plate and subnail tissue caused by nail lesions. Because topical drugs are not easy to enter the nail plate and the nail plate grows slowly, the treatment is based on oral drug therapy, so the treatment is more difficult, the key is to adhere to the medication. After a full course of application of terbinafine for a decade of onychomycosis, the longer it takes to see results if the diseased nail grows more slowly, and the shorter it takes to see results if the diseased nail grows more quickly. Adverse reactions such as nausea, abdominal pain, skin rash and liver function abnormalities may occur after using terbinafine. If these symptoms occur, it is recommended to stop the medication and seek medical attention. Hypersensitivity to terbinafine or any component of the preparation, as well as severe hepatic and renal insufficiency need to be contraindicated in patients. It is recommended that patients who have grown gray nails for more than ten years go to the hospital in time and use Terbinafine under the guidance of the doctor’s standardization, and not to use it privately.