Know what Cialis is used for, how to take it, and which side effects to expect when starting it. By controlling the enzyme, tadalafil helps to maintain an erection after the penis is stroked by increasing blood flow to the penis. Without physical action to the penis, such as that occurring during sexual intercourse, tadalafil will not work to cause an erection. Find patient medical information for Tadalafil (Cialis, Adcirca, and others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Typical dosage for ED/BPH: One 5-mg tablet every day. When to take your dose: Take this drug at about the same time each day. Don’t take tadalafil more than once per day. Take this medication by mouth, with or without food, as directed by your doctor. Do not take tadalafil more often than once daily. The manufacturer directs to swallow this medication whole. However, many similar drugs (immediate-release tablets) can be split/crushed. Follow your doctor's directions on how to take this medication. Cialis relaxes muscles of the blood vessels and increases blood flow to particular areas of the body. Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). When therapy for BPH is initiated with CIALIS and finasteride, the recommended dose of CIALIS for once daily use is 5 mg, taken at approximately the same time every day for up to 26 weeks. When therapy for BPH is initiated with CIALIS and finasteride, the recommended dose of CIALIS for once daily use is 5 mg, taken at approximately the same time every day for up to 26 weeks. When therapy for BPH is initiated with CIALIS and finasteride, the recommended dose of CIALIS for once daily use is 5 mg, taken at approximately the same time every day for up to 26 weeks. Dosage for ED and BPH For people who have ED and BPH (ED/BPH), the recommended starting dose of tadalafil is 5 mg. You’ll usually take this once daily. This is also the maximum recommended.