You take one 2. That’s not to say there aren’t just as many illegitimate sites. Occasionally tadalafil can make you feel dizzy. Stendra avanafil : This is an as-needed medication taken 30 minutes before sex and can last up to six hours. Only sildenafil Viagra is available without prescription. · It treats erection problems by increasing blood flow to the penis. It’s also used to treat symptoms of an enlarged prostate (benign prostatic hyperplasia or BPH). At $ for 30, 5MG Tablet, Cialis is an expensive prescription drug. You can lower the cost of Cialis to $ for 30, 20mg Tablet of generic Cialis. Tadalafil is available on prescription only. It comes as tablets. You can only get it on prescription for erectile dysfunction if you have a specific condition such as multiple sclerosis or a spinal cord injury. Tadalafil is not usually used to treat benign prostate enlargement because there is not enough evidence about how well it works. Cialis comes as a tablet you swallow. It contains the active ingredient tadalafil. (An active ingredient is what makes a drug work.) Keep reading for details on Cialis and cost, and how to save.