The use and abuse of steroids, even with dubious safety protocols such as cycling and avoidance of oral steroids, can lead to significant health problems -- and rare fatalities, usually from cardiovascular complications. ("Cycling" is the practice of stopping use for several weeks within, say, a 10-week period.) Although different steroids and their routes of administration--injection, by mouth or even inhalation have different adverse effects--there is no doubt that in various circumstances anabolic steroids cause adverse liver, kidney, sexual and reproductive, cardiovascular, and mood effects.
To reiterate, our current understanding of the adverse cardiovascular effects of anabolic steroids is based on rather limited information gathered from a small number of research studies. The available reports, though, certainly give a glimpse of unwanted cardiovascular effects that may occur, even if the causal mechanisms are not yet understood. Going forward, we are unlikely to have large-scale prospective studies to gather more information and additional retrospective studies are likely to have the methodologic pitfalls I mentioned above. Given our current understanding, athletes who choose to use anabolic steroids should be aware of the possibilities of high blood pressure, unfavorable lipid profile, structural changes in the heart, and even heart attack or SCD.
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.