In contrast to other methods of erectile dysfunction treating that involve injection into the genital organ or other medical procedures, "Viagra" is the simple and convenient drug that's easy in usage. You just take the "Viagra" pill when you're going to have a sexual contact

According to the data of laboratory research held in urology department of Cologne university the latest drug for potency stabilization - "Levitra" - is 10 times more effective than "Viagra" and 13 times more effective than "Cialis" in blocking the effect of phosphodiesterase enzyme of type 5 (PDE-5). Process of PDE-5 blocking underlies the effect of these three drugs for potency normalization: due to this process blood inflows to penis tissues and that causes erection.