Ever since Viagra exploded on the market eight years ago, it's been almost impossible to watch television without seeing ads for drugs designed to enhance a man's sexual experience.
The popularity of these pharmaceuticals has spawned a whole new line of natural male enhancement products. And they are among the hottest-selling products in the $26 billion herbal supplement -- or as the makers call them, nutraceutical -- industry.
Many of these products suggest extraordinary results. For example, four years ago, Berkeley Nutraceuticals, the largest seller of male enhancement pills -- said its Enzyte product would grow your penis up to 41 percent.
Recently, the company moderated those claims, and they now simply promise firmer, fuller-feeling, better-quality erections
Consumer advocate, Dr. Sydney Wolfe, says that with respect to the growing industry of natural male enhancement products, safety is unknown and effectiveness is unproven. "You've got an industry that just can invent something, grind up some root, put it in a bottle, [and] sell it," said Wolfe, author of "Best Pills, Worst Pills."
"Primetime Live" tested some Enzyte it purchased in March. The ingredients listed in the product packaging were found in the pills, including ginseng root, ginko biloba and saw palmetto.
Supplement makers say the product's ingredients have been used as sex enhancements for centuries, but Dr. Franklin Lowe, a leading New York urologist expressed serious doubts about whether any of them could enhance male sexuality.
"It's very enticing. It's good marketing. But to my knowledge, there's no clinical evidence that supports any of those claims," he said.
The manufacturer of Enzyte told ABC News that it had recently changed the formulation and that the product continues to work as advertised.
Still, the popularity of such products has created overnight millionaires -- like Michael Consoli and his nephew Vincent Passafiume, whose company C.P. Direct sold a male enhancement product called "Longitude."
"They were paying $2 [for] a bottle of pills that they were selling for $40. And they were selling one hell of a lot of them," said Larry Warfield, an accountant who helped Arizona investigate a company called C.P. Direct, which sold "Longitude," a male enhancer.
Consoli and Passafiume found their recipe on the Internet, but their real secret ingredient was advertising. They guaranteed their pill would increase penis size 26 percent in just 12 weeks.
They spent more than $1 million a month on advertising, and in just one year, C.P. Direct was selling everything from "Stature" -- guaranteed to make you taller, to "Full and Firm" a pill promising to enlarge women's breasts.
C.P. Direct didn't have a stitch of scientific proof that its products actually worked, but it still took in $75 million in revenue.
It seems the only thing Longitude was proven to increase was the company's bank account. Consoli and Passafiume bought more than a dozen exotic cars and gold-plated furnishings in 17 homes in different states -- all paid for by their pills.
Today, there are dozens of companies selling male sexual enhancement pills.
Although they sell items that resemble drugs and suggest powerful results, supplement makers -- unlike drug makers -- are not obligated to prove the effectiveness or safety of any of their products.