Erectile Dysfunction
"Taking 20mg, all I can say is &quot;guess it is ok, when it works.&quot;  I have tried the top three oral medications for ED.  I can say that when it works it stimulates a very firm erection.  However, I have begun to feel like soon as it takes effect I have better take advantage. I normally do suffer headaches mild to moderate, and get very flushed.  We also have noticed that the time it takes to start working has varied from 1 - 4 hours."