I also ordered http://viagrawithoutdoctorprescriptionusa.com - viagra without a receipt , I decided to once a good dose of 100 mg. Everything worked great in bed! The erection was at a time of strong and long. But after a couple of hours we began severe headaches. I do not see a doc, and in this situation, but just looked on the internet reviews, stories and experiences of others to find themselves right answer on how to take these drugs.