You take one 2. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects. Tadalafil can be synthesized starting from D – tryptophan methyl ester and piperonal via a Pictet—Spengler reaction. Erectile dysfunction can be caused by a variety of factors , including age, cardiovascular problems, diabetes, and other conditions that affect nerve function or blood flow. Both options require valid medical documentation, but some online services only require a health questionnaire to be filled out and reviewed for approval—meaning no face-to-face video interaction is needed. Continue to take tadalafil even if you feel well.Compare prices and print coupons for Cialis (Tadalafil (Cialis)) and other drugs at CVS, Walgreens, and other pharmacies. Prices start at $ diagnosis or treatment. GoodRx is not offering advice, recommending or endorsing any specific prescription drug, pharmacy or other information on the site. GoodRx provides no warranty for any. 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. Cialis is a medication approved by the Food and Drug Administration (FDA) often used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH) in those assigned male at birth.