Cialis: Is one right for you? Also, avoid grapefruit juice, which can have the same effects as prescription drugs, despite being much more delicious. That means seven out of 10 people who take these drugs as prescribed will have more frequent or longer-lasting erections. Viagra vs. How long does it take for Cialis to peak?Generic name: Tadalafil mg Dosage form: tablet, film coated Drug class: Impotence agents. Medically reviewed by test1.ru Last updated on  · Drug Images. Cialis (tadalafil) is prescribed to treat erectile dysfunction and symptoms of benign prostatic hyperplasia. It comes as a tablet that’s taken as needed or . Tadalafil is a prescription drug. It comes as an oral tablet. Tadalafil oral tablet is available as the brand-name drugs Cialis and test1.ru’s also available in a generic form.