Iodophor is not generally used to treat gray nails. Povidone-iodine is a disinfectant with broad-spectrum bactericidal effect, which can kill fungi, bacteria part of the viral body, protozoa propagation body. Gray nail is caused by fungal infection, generally ordinary medical iodine povidone concentration is low, and can not play a role in the treatment of gray nails, clinical also do not use it to treat gray nails. The preferred drug for treating gray nails is oral antifungal drugs, such as itraconazole capsules, terbinafine tablets and so on. When there are contraindications to oral antifungal drugs, drugs such as amorolfine application can be used externally, and patients should use the drug according to the course of treatment and in sufficient quantity in order to achieve the effect of completely eliminating the fungal infection. When using medication to treat gray nails, you should follow the doctor’s instructions, if you are allergic to the medication or its ingredients, you can combine with the doctor’s advice, change other medication. Patients are advised to pay attention to personal hygiene and avoid scratching other parts of the body with the diseased nails, so as not to cause infections in other parts of the body.