In , Pfizer scientists discovered that sildenafil, which also inhibits the PDE5 enzyme, caused penile erection in males participating in a clinical study of a heart medicine. Introduction In the age of e-commerce and digital advancements, more and more consumers are shifting to online platforms for their purchases. A deep dive into the ins and outs of purchasing this popular medication online, ensuring that you make informed decisions every step of the way. Many rogue pharmacies sell counterfeit or substandard products that can be harmful. Also tell your doctor if you or any of your family members have or have ever had an eye disease such as retinitis pigmentosa an inherited eye condition that causes loss of vision or if you have ever had sudden severe vision loss, especially if you were told that the vision loss was caused by a blockage of blood flow to the nerves that help you see.We would like to show you a description here but the site won’t allow more. Cialis comes in several strengths: milligrams (mg), 5mg, 10 mg, and 20 mg. The Cialis cost per pill and daily cost depend on several factors, such as: the strength prescribed by your.  · Cialis (tadalafil) is prescribed to treat erectile dysfunction and symptoms of benign prostatic hyperplasia. It comes as a tablet that’s taken as needed or once per day, depending on the.