How Steroid Use Changes Testosterone/Epitestosterone Ratio

Exogenous consumption of anabolic steroidal hormone – testosterone has been associated with a significant increase in the muscle mass, stamina and endurance making it one of the most abused synthetic hormones, topping the charts ever since its discovery! For decades, a diverse array of anabolic steroids has ceremoniously been abused for exogenous performance enhancement. So, for years efforts have been directed to find an appropriate biomarker to assess the physiologically normal levels of this magical potion and that’s how T/E ratios were discovered!

Testosterone/Epitestosterone (T/E) ratio is a measure of relative proportions of these two steroidal male sex hormones in the body by measuring levels of testosterone glucuronide (TG) and epitestosterone glucuronide (EG) in the urine. TG is a by-product of testosterone which increases with an increase in the amount of testosterone while EG is unrelated to testosterone metabolism and serves merely as a reference point. This ratio is significant because it is an indicator of a pathological condition or external administration of any of the respective sex hormones making it an important biomarker. Often under normal conditions, the T/E ratio has been found to be roughly equal to 1:1. However, the overall T/E ratio may deviate significantly from the normal values in case someone catches flu or if he tries to get that extra edge in that Saturday night game in which case, the testosterone level may increase while the epitestosterone levels tend to remain unaffected! Still, as the saying goes, nothing in this world exists without any use or purpose! Epitestosterone, a poor inactive stereoisomer of testosterone which unfortunately has not been blessed with any of the magical powers of its epi-less brother, has found its use as a very good masking agent for testosterone abuse! If an additional amount of epitestosterone is administered to such dopers, it may make his/her T/E ratios look pretty decent.

While some steroids, NSAIDs, & opioid analgesics may change T/E ratios in prostaglandin-mediated processes, some other anabolic steroids like androstenedione are the immediate precursors of testosterone which may increase the excretion of epitestosterone and its metabolites while decreasing that of its precursor thus effectively shifting the marker ratios!

However, there’s a little twist to the story! Various studies reveal serious weaknesses in the T/E ratio test used by various anti-doping organizations as a biomarker. One of the reports published in the Journal of Clinical Endocrinology & Metabolism successfully argues that the production of TG from testosterone is primarily controlled by an enzyme (UGT2B17) produced by a specific gene that has many common variants coding for enzymatic variants with different levels of activity. So, wildly different testing results can be expected with the intake of same doses of testosterone! In lieu of this, the validity of T/E based testing has widely been debated and alternate methods of hormone testing have been suggested.