Cialis - instead of taking a 20mg (36) hour tablet can I take four 5mg daily tablets?

My Dr had prescribed the 20mlg Cialis pills for me originally and they work better sometimes than others. I found out that you can buy 4 of the 5mlg Cialis pills cheaper than you can buy 1 of the 20mlg Cialis pills! Go figure!!! So I told my Dr about it and he started writing my Cialis prescriptions for the 5mlg pills instead of the 20mlg pills. So he told me I could take 4 of the 5mlg pills with the same effect as 1 of the 20mlg pills! They do give me a slight headache sometimes but not all of the time! I still don't get it that I can buy 4 of the 5mlg Cialis pills cheaper than 1 of the 20mlg ones??? As I said before, go figure on that one?!

I personally, from time to time, take 4x5mg once in a while (not every day). It seems to work OK in terms of efficacy as well as in terms of side effects. This is in my case. Hope it helps.