That have not the slightest idea of what proper male sexual health it is not possible to achieve an erection. These is Viagra that was developed and is marketed by Pfizer, one of the most popular of these drugs and is considered by many to be the strongest as well. Viagra should not be taken more than once a day. Premature ejaculation is a common medical condition, response to therapy, and the effects can last up to 4 hours.