All anabolic steroids suppress natural testosterone production. However, the rate of suppression often varies greatly from one steroid to the next. Although it does suppress natural testosterone production, Primobolan’s rate of suppression is much less dramatic than many anabolic steroids. In a therapeutic plan, it is actually possible to keep the total rate of suppression below 50%. This could be low enough to keep some from falling into a low level condition despite the reduction. However, performance level doses will be another story. Dramatic suppression is all but assured with such doses making the inclusion of exogenous testosterone extremely important. Men who do not include exogenous testosterone will more than likely fall into a low testosterone condition. Not only does this carry numerous possible bothersome symptoms, it is extremely unhealthy. Women, despite needing testosterone will not have a need for exogenous therapy when using Primobolan.
Once the use of Primo and all anabolic steroids has come to an end, natural testosterone production will begin again. You will find this is one of the easiest steroids to recover from when it comes to testosterone production. Most men are encouraged to implement a Post Cycle Therapy (PCT) plan once use is discontinued. This will speed the recovery process up. It will, however, not return you to normal on its own. This will still take time. However, a PCT plan will ensure you have enough testosterone for proper bodily function while your levels continue to naturally rise. Those who do not implement a PCT plan, while they may recover it will take far longer. There’s really no reason to forgo the PCT process if you’re going to be off cycle for any decent length of time.
An important note on natural testosterone recovery. Natural recovery assumes no prior low testosterone condition existed. It also assumes severe damage was not done to the Hypothalamic-Pituitary-Testicular-Axis (HPTA) through improper steroidal supplementation practices.
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.