erectile dysfunction
"I took Viagra 50mg for several years and it was fantastic.  Then insurance company changed coverage and would only pay for Cialis.  Followed the Dr and drug company instruction to cut 20mg in half and use that. Two hours later, and with the proper "motivation" it wasn't kicking in.  Didn't kick in until the next morning, and I'm not 100% sure it was the pill.  Bottom line, Cialis seems to kick in at unpredictable times, while viagra was a guarantee 60-90 minute fun time"