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). In combination with sexual stimulation, tadalafil works by increasing blood flow to the penis to help a man get and keep an erection. Tadalafil is also used to treat the symptoms of an enlarged prostate (benign prostatic hyperplasia-BPH). 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. 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. 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. Tadalafil relaxes muscles of the blood vessels and increases blood flow to particular areas of the body. Tadalafil under the name of Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Cialis is a popular ED medication. Find out everything you need to know about this doctor-prescribed medication including usage, effectiveness, safety considerations, and where to buy online. Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more. 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. Know what Cialis is used for, how to take it, and which side effects to expect when starting it.