So, which drug is better - Cialis, Viagra or Levitra? Let's take it in order. The first one to appear on the shelves of pharmacies was Viagra. The active ingredient is Sildenafil, developed by Pfizer. It was originally created to fight angina. However, clinical trials have shown that Sildenafil copes poorly with this purpose. But it turned out that the drug is effective in the fight against male impotence. In about 84% of cases, Viagra contributed to achieving a sustained erection.