Nandrolone, or 19-Nortestosterone, is one of the most widely used synthetic anabolic-androgenic steroids by athletes who need power and muscle strength. It is derived from testosterone, the main sex hormone produced in man, but has by far more powerful anabolic properties.
Athletes use nandrolone to accelerate muscle growth and increase lean body mass, strength and aggressiveness. Despite inconclusive scientific data, nandrolone is also used for faster recovery from intense training. Whatever the intention, the side-effects of nandrolone are dangerous and should be taken very seriously.
Nandrolone was first banned in 1976. The finding of a potential doping offence with Nandrolone use is based on the detection of the two major metabolites 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE). These metabolites can be detected in the urine for several days after oral ingestion or for months after injection into the muscles. Elimination is strongly dose-dependent and individual.
Over the last decade, there have been numerous doping cases involving nandrolone that have led to various hypotheses concerning the origin of nandrolone metabolites found in the urine of athletes. Several factors have been identified that might influence a positive finding.
For example, physical effort can have different, but certainly no systematic effects, on the excretion of nandrolone metabolites, depending on an individual's metabolism. A natural source for production within the body is also considered.
If you want to know why the case of nandrolone is so complicated and why the unintentional intake with nutritional supplements does not protect a player from being sanctioned, read more about it.