The original formulation of Cialis, also known as Cialis for Use as Needed, was first brought to market in 2003 and is available in tablets of 10 and 20 milligrams. The starting dose is usually 10 milligrams but can be increased to 20 if necessary to achieve an erection. Sometimes called the “weekend pill,” Cialis for Use as Needed is effective for up to 36 hours. The pill usually takes effect within one hour and sometimes is effective within 30 minutes.
Approved by the FDA in 2008, Cialis for Daily Use comes in 2.5- and 5-milligram tablets. Doctors often start patients on the 2.5-milligram dose and increase it to 5 milligrams if needed. Take the pill daily, and you should be able to achieve and maintain an erection suitable for intercourse when the need arises.
The active ingredient in both forms of Cialis is tadalafil.