Your healthcare provider can help you determine the right dosage for you. National Library of Medicine. Cialis lasts longer. Brian Staiger Pharm. Cialis stays in your system for up to 36 hours and may provide support for erections during that entire time. Answered By: Dr.Drug Facts Common Brands Cialis Drug Class PDE-5 inhibitor Controlled Substance Classification Not a controlled medication Generic Status No lower-cost . Yes. The active ingredient for Cialis, tadalafil, is also the active ingredient for Adcirca, a brand-name drug used to treat pulmonary arterial hypertension, or high blood . If a pharmacy, or someone in the United States is offering generic Cialis (tadalafil), be very wary as there is a good chance it is fraudulent. If you are getting it .