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 a bulking agent, the effects of Masteron will prove to be rather weak. It is possible the hormone could provide gains in mass similar to Primobolan (which wouldn't be that strong either) if the total dose was sufficiently high. However, the relative gain in size will be moderate with many anabolic steroids being far more suited for this period of steroidal supplementation. Masteron does not aromatize and is not estrogenic; in fact, it shows anti-estrogenic traits in the body and binds to aromatase instead of other substrates. This is why it has been effective in the treatment of breast cancer.