My doctor wrote the script for 20mg and told me to break them in half to save money. My appraisal of Cialis is it is a very transparent drug. You don't know you've taken it until it's called for. I can't speak for anyone with a serious ED problem, but as a diabetic with the symptoms just beginning to appear, it is fantastic! I forgot what it was like to be 14 years old again... It's not an aphrodisiac in the traditional sense, but the improvement has sparked more interest and activity from my wife, so in that regard, it is a bit of an aphrodisiac.
Biggest side effect so far is rolling over in my sleep with a nocturnal erection and pole vaulting off the bed!

Summary: 20mg halved, each lasts 2 days, 6 tabs per month would give you 24 days of effect. My local pharmacy is charging 11 bucks each.