The Cialis effective time — how long it will aid you in getting an erection — is 24 to 36 hours. Cialis Daily will remain active in your system for around 24 hours whilst Cialis lasts up to 36 hours. Cialis stays in your system for up to 36 hours, and you can take it daily. Communicate with your partner and interact with them after you take Cialis to help the medication work. Summary Cialis and Viagra are both pills for treating erectile dysfunction.The recommended starting dose for Cialis intended for once daily use is mg, take at the same time each day, without regard to timing of sexual activity. This may be increased to 5mg/day based on need and tolerability. May be taken with or without food. Cialis is available as a generic, under the name tadalafil. 3. Cialis is an effective treatment for mild to severe ED. On the standard starting dose of 10mg of the active ingredient in Cialis, tadalafil, 71% of men reported an erection suitable for sex. On a higher 20mg dose of tadalafil, 73% of men reported improved erections. On Cialis Daily, 84% of men reported improved erections and 72% preferred. CIALIS for once daily use is a lower dose you take every day. • Do not take CIALIS more than one time each day. • Take one CIALIS tablet every day at about the same time of day. You may attempt sexual activity at any time between doses. • If you miss a dose, you may take it when you remember but do not take more than one dose per day.