Neither. It's all in your head. What the pills do is help you to get very hard and then get hard again over and over in a 1-4 hour time period. Everybody is different, it only lasted 1 hour for me then my body just simply burns it up. Cialis lasts a few days, i.e. the weekend pill. Viagra past 1-4 hours depending on your body. People take them and their mind relaxes believing they can last longer, so they do. I can do that same trick with you by giving you a sugar pill. If you have problems getting an erection, that's why you take it. Other than that, it's for sport haha. If you are going to buy, get both, Viagra and Cialis, try them both to see which you like better. It will not cure anything, it's all in your head brother, believe me, but it is fun to use. Good luck.