Cialis (tadalafil) can be prescribed for the treatment of a widespread condition - male impotence. Before taking this medicine you should visit a doctor and tell him about any of your health conditions that may potentially interfere with the treatment. Also report any allergies and any drugs you are taking at the moment, including nutritional supplements, vitamins and other products. Before you start taking any new medicine make sure you tell the doctor that is going to give you a prescription that you are taking Cialis. Take this drug about 30-60 minutes before you are planning to have sex. Once taken, Cialis can provide for up to 36 hours of efficiency, although this period may be different for different people depending on their health condition and other factors than need to be taken into consideration. Buy cialis online.