There is not much difference between taking tadalafil three hours in advance and five hours in advance. Tadalafil usually refers to tadalafil tablets, is to improve male erectile dysfunction PDE5 inhibitors, usually half an hour before coitus, after taking the drug once sexual stimulation can play a role in the drug effect up to 36 hours, that is to say, three hours in advance and five hours in advance to take there is no difference, can play the same effect. Tadalafil tablets may cause headache, dyspepsia, dizziness after taking the drug, but can be gradually improved with time to disappear; in addition, women, myocardial infarction, unstable angina, or angina pectoris during sexual intercourse and other patients need to be prohibited from taking the drug. Tadalafil tablets belong to the prescription drugs, medication need to have a professional doctor’s guidance only, can not be used recklessly.