Nandrolone, known commercially as Deca-Durabolin, is an anabolic steroid occurring naturally in the human body, albeit in small quantities. Its presence is indirectly detectable in urine tests by testing for the presence of 19-norandrosterone, a metabolism product of this molecule. The International Olympic Committee has set a limit of 2 nanograms per millilitre of urine as the upper limit, beyond which an athlete is suspected of doping.