Researchers test male birth control pill.

A birth control pill for men? It could be a reality soon, along with other birth control options such as creams, injections and even implants for guys.

Researchers are working on birth control, for men. But it's a challenge since men make 1,000 sperm a second. To be an effective contraceptive, sperm count has to go down to zero.

Michael Lehmann has been involved in five testosterone-based clinical trials. He's taken daily pills, monthly injections, a cream he rubbed on his shoulder, and even had an implant.

"There were very minor side effects, um, I had some slight acne on my scalp," Lehmann said.

But testosterone could increase the risk of heart disease and prostate cancer. That's why Dr. John Amory is blocking vitamin A in the testicles, which in turn blocks the development of sperm.