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 The recommended starting dose of CIALIS for once daily use is 2.5 mg, taken at approximately the same time every day, without regard to timing of sexual activity. The CIALIS dose for once daily use may be increased to 5 mg, based on individual efficacy and tolerability. Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more. Tadalafil is also available under the brand names Cialis and Adcirca. Keep reading for specific information about the dosage of tadalafil, including its strengths and how to take the medication. CIALIS for Once Daily Use CIALIS for once daily use has not been extensively evaluated in patients with mild or moderate hepatic impairment. Therefore, caution is advised if CIALIS for once. For erectile dysfunction, take Cialis just before sexual activity but not more than once per day. Cialis can help achieve an erection when sexual stimulation occurs. Cialis is an ED medication that can be taken orally before sexual activity, but not more than once daily. Learn how to get the maximum effects from Cialis and avoid side effects. Learn about tadalafil (Cialis) usage and dosing. Read the latest news and reviews about the drug as well as potential side effects and popular alternatives. 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). 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.