Tadalafil is its active ingredient and is available as a generic drug. Your doctor will help you decide the best time for you to take tadalafil before sexual activity. Though this growth is not cancerous, prostate cancer and BPH can co-occur. John’s wort. Take tadalafil at around the same time every day. What special precautions should I follow?Tadalafil (Cialis) is taken by mouth either as needed before sexual activity or once daily for erectile dysfunction (ED).It’s also taken once daily to treat symptoms from an enlarged prostate (benign prostatic hyperplasia, or BPH).Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include . Dosage range: mg to 5 mg. Frequency: once daily, regardless of the timing of sexual activity. Cialis’s recommended dosage when it’s taken as needed for ED is as follows. Dosage range: 5 mg to 20 mg. Frequency: one dose at least 30 minutes before sexual activity, with a maximum of one dose per day*. Roman is a telehealth prescription service and online pharmacy that provides prescription Cialis for ED and a host of other conditions, like hair loss, cold sores, and premature ejaculation. When.