Heavy consumption of the essential amino acid lysine (as indicated in the treatment of cold sores) has allegedly shown false positives in some and was cited by American shotputter C. J. Hunter as the reason for his positive test, though in 2004 he admitted to a federal grand jury that he had injected nandrolone.  A possible cause of incorrect urine test results is the presence of metabolites from other AAS, though modern urinalysis can usually determine the exact AAS used by analyzing the ratio of the two remaining nandrolone metabolites. As a result of the numerous overturned verdicts, the testing procedure was reviewed by UK Sport . On October 5, 2007, three-time Olympic gold medalist for track and field Marion Jones admitted to use of the drug, and was sentenced to six months in jail for lying to a federal grand jury in 2000. 
As for testosterone; you understand how important testosterone is to the human body; in-fact, it is one of the most important hormones we produce. Through the use of anabolic steroids our natural testosterone production is suppressed and while total suppression varies with each and every steroid, Nandrolone steroids have a 100% suppression rating. Without testosterone supplementation your body will not have the testosterone it needs to function properly; no matter how special you believe you may be or what your friend may have told you, if you supplement with a Nandrolone hormone you wont be making any testosterone. It is important to note when Deca 300 use comes to and end and once it and any other anabolic steroids have cleared your system your natural testosterone production will begin again; however, during the actual cycle it will not exist. By supplementing with exogenous testosterone we eliminate this problem, we provide our body with the testosterone it needs to function and as a bonus only enhance our Deca 300 use as the testosterone hormone in of itself is highly anabolic.