Like other erectile dysfunction treatments , tadalafil works by preventing the action of a chemical in your body called phosphodiesterase type 5. Daily use of “on-demand” medication is not recommended. The increase in blood flow causes an erection, allowing males to achieve and maintain an erection. If you wish to benefit from the advantages of taking tadalafil daily , you should start by taking tadalafil 2. The combination of these medications with Cialis Tadalafil may add to the blood-pressure-lowering effect of these medications. Important: Tadalafil will not make you last longer by prolonging the time it takes to ejaculate, but it can allow you to maintain a firm erection for a longer period of time. All orders are checked by a pharmacist to ensure that it is safe to prescribe tadalafil.Taking tadalafil with a nitrate medicine can cause a sudden and serious decrease in blood pressure. Some medicines can cause unwanted or dangerous effects when used with Cialis. Tell your doctor about all your current medicines, especially riociguat (Adempas). Cialis 20 mg (C 20) View all images. The lowest price on for generic Cialis (tadalafil) 20 mg is $ per tablet for 88 tablets at PharmacyChecker-accredited online pharmacies. Lowest U.S. Pharmacy Coupon Price: $ per tablet for 90 tablets. . Cialis (tadalafil) is a popular medication used to treat erectile dysfunction. It’s available in tablets ranging from mg to 20mg. It can cost more than $ for a month’s supply, depending on the dosage you need and the pharmacy you visit. You can save more than 90% on the average retail price at certain pharmacies by using a GoodRx coupon.