Approximately a fifth of the administered steroid binds to progestin receptors (due to the absence of carbon atom at position 19), and therefore are not excluded such reactions as suppressing gonadotropic hormone secretion, increased prolactin production, a significant reduction in libido. Weak erection - most pronounced and severe consequence of abusing Nandrolone Decanoate. If you exceed the recommended dosage and duration of the cycle, it may cause rhinitis, headache, back pain, rash. In general, the side effects of Nandrolone Decanoate are rather the exception than the rule.
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 steroid 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.