Like other erectile dysfunction treatments , tadalafil works by preventing the action of a chemical in your body called phosphodiesterase type 5. It has the same active ingredient as Cialis , but it is the generic non-branded version. Erectile dysfunction is caused when an enzyme called PDE5 is present in the penis. You should check with your doctor or pharmacist to see if it is safe for you to take. The drug is approved for use in adults. Alternatively, Cialis may be prescribed as an as-needed treatment for ED, to be taken before sexual activity. If you have not been successful after 8 separate attempts, you should speak to your doctor or pharmacist about increasing the strength to tadalafil 5mg tablets.$ (save %) local_offer_outlined Avg retail price $ medication_outlined Availability Available See GoodRx coupons warning Are you looking for information on Adcirca (tadalafil) instead? What is Tadalafil (Cialis)? Drug Facts Common Brands Cialis Drug Class PDE-5 inhibitor. How does this compare with the cost of other strengths ( mg, 5 mg, 10 mg)? Cialis comes in several strengths: milligrams (mg), 5mg, 10 mg, and 20 mg. The Cialis cost per pill and daily cost. Cialis comes in several different strengths, including: milligrams (mg) 5 mg. 10 mg. 20 mg. The cost for these different strengths depends on whether you have insurance, your individual plan.