I have tried to use Cialis on five different occasions. I get about 80% erect then "hit the wall". That is it. after the 80% erection, it goes pretty much totally flaccid. Then ALL is lost. I am overweight and in my mid 60's. I had radiation therapy for prostate cancer last year. WHAT is next ? Is it possible to use 2 20 mg tablets at once? It is WAY expensive for NOTHING !!!