With out a prescription only. Ive used like the pills they sell at gas stations and make your penis big pills and they all pretty much have the same thing it looks like. If i take too much they kinda work but am so sick feels like am going to die. And i might have a ragin hard on for awhile but am hurting bad. If i dont take enough really dont feel a affect. What is proven to work with out side effects. Ive tried maca kinda worked for a week or two than it kinda wore off.