Sildenafil is taken on an as-needed basis, three times a month is fine, but up to once a day. Sildenafil, commonly known by the drug name Sildenafil Citrate Tablets, is primarily used to treat erectile dysfunction, and the recommended dosage for most patients is 50mg, taken at any time within 0.5 to 4 hours prior to sexual activity. It is usually taken as needed one hour before sexual activity, and depending on the patient’s tolerance and efficacy, the dose may be increased to 100mg (the maximum recommended dose) or decreased to 25mg at the discretion of the patient, up to a maximum of once a day, and sildenafil does not work when there is no sexual stimulation. Some patients may experience headache, dizziness, rash, indigestion and other adverse reactions after taking the drug, patients who are allergic to the product are prohibited, women are prohibited, nitrates and guanylate cyclase stimulants can not be used with this product. So patients can take three times a month, it is recommended that patients who are not feeling well go to the regular hospital in time, and follow the doctor’s instructions to take medication as needed.