Tadalafil does not have a specific course of treatment, clinically, it is generally taken for 2 to 3 weeks. Tadalafil is the treatment of male erectile dysfunction drugs, how long a course of treatment, can not be clearly judged, and the patient’s condition, no strict meaning of the “course of treatment”, clinically, the time to take the drug from 2 weeks to 3 weeks ranging. After 2 to 3 weeks, the patient’s condition will determine whether to continue to take the drug. Patients should follow the doctor’s instructions. The use of tadalafil may cause adverse reactions such as headache, back pain, and indigestion. Tadalafil is contraindicated in people who are allergic to any of the ingredients in the product, patients who are taking any form of nitrates, guanylate cyclase stimulators, women, children and other people. The drug should be applied under medical supervision.