Tadalafil was found to have similar benefits for lower urinary tract symptoms as the usually prescribed tamsulosin. Tadalafil is sometimes taken as needed, usually at least 30 minutes before sexual activity and not more often than once every 24 hours. Do not chew on it or break it apart. If you drink a large amount of alcohol more than five glasses of wine or five shots of whiskey while you are taking tadalafil you are more likely to experience certain side effects of tadalafil such as dizziness, headache, fast heartbeat, and low blood pressure. Mechanism of action[ edit ] Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and the smooth muscle of the corpus cavernosum. Ensure that the product description mentions this. · The typical dose for once-daily Cialis for ED is milligrams (mg) to 5 mg. When used as needed for ED, the usual Cialis dose is 10 mg (with a maximum daily dose of 20 mg). The typical dose of. Hims offers brand name Cialis as a monthly supply of 5-mg tablets that can be taken daily. Generic Cialis (tadalafil) is available in mg, 5-mg, mg, mg, and mg tablets for daily or as. Tadalafil (Cialis) is used to treat erectile dysfunction (ED, impotence; inability to get or keep an erection), and the symptoms of benign prostatic hyperplasia (BPH; an enlarged prostate) which include difficulty urinating (hesitation, dribbling, weak stream, and incomplete bladder emptying), painful urination, and urinary frequency and urgency in adult men.