Tadalafil has been extensively studied for ED. How Effective Is Cialis? If you are taking tadalafil on a regular schedule, take it at around the same time every day. You can see an in-person provider or speak with a doctor virtually. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Tadalafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow more easily.AdGet Deals and Low Prices On Top Products At Amazon. We Offer an Extensive Selection Of Everything Else Store At Amazon. Order Today!Types: Pet Supplies, Beauty & Personal Care, Anxiety, Pharmacy, Medical Care and more. Tadalafil (Cialis) is used to treat erectile dysfunction (ED, impotence; inability to get or keep an erection), and the symptoms of benign prostatic hyperplasia (BPH; an enlarged prostate) which include difficulty urinating (hesitation, dribbling, weak stream, and incomplete bladder emptying), painful urination, and urinary frequency and urgency in adult men. Tadalafil is a generic version of the prescription drug Cialis. Doctors prescribe it to treat erectile dysfunction and benign prostatic hyperplasia. It helps relieve erectile dysfunction by.