成人快手

5 Live's Rick Edwards speaks to "biohacker" Ben Greenfield, a 40-year-old who claims to have a biological age of nine.

Biohackers tinker with their biological processes in order to "optimise" themselves.

Sometimes they use tried and trusted science, other times the practices can be more unusual.

Ben describes some of the "techniques" he uses and explains why he has become known in the industry as "penis guy".