You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail. Reading is good for you Reading about what’s good for you is even better. You’ll also need to fill out a medical questionnaire with answers about your medical history, current medications, and lifestyle habits. From Mayo Clinic to your inbox Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Patients who experience symptoms upon initiation of sexual activity should be advised to refrain from further sexual activity and seek immediate medical attention.Cialis and generic tadalafil are available in four different strengths— mg, 5 mg, 10 mg and 20 mg—but which one should you take? If you’ve never tried Cialis before, your doctor will likely start you on a low dose, like mg or 5 mg. quality Usually, generic drugs aren’t available until the expiration of the brand name’s patent. Eli Lilly and Company’s patent for Cialis expired in , opening the market to generic. 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.