A “Pheraplex” Capsule Labeled as Desoxymethyltestosterone From the Market Turned Out to Be 17,17‐Dimethyl‐18‐nor‐5α‐androst‐13‐en‐3β‐ol

ABSTRACT In an effort to conduct a desoxymethyltestosterone (DMT) administration study to replenish excretion urine inventory of Beijing Anti‐Doping Laboratory for quality assurance purpose, a product labeled as “Pheraplex” was purchased from the internet. The product's label indicated that each capsule contained 10 mg of 17α‐methyl‐etioallocholan‐2‐ene‐17β‐ol (DMT), along with medicinal corn starch and gelatin. To verify the product's contents, gas chromatography tandem quadrupole mass spectrometry (GC–MS/MS) was employed to analyze the active ingredient and compare it with the reference materials of DMT. Surprisingly, the results revealed that the product did not contain DMT or any other steroids monitored in the initial testing procedure of our laboratory. Subsequently, nuclear magnetic resonance was utilized to identify the compound's structure, which was determined to be 17,17‐dimethyl‐18‐nor‐5α‐androst‐13‐en‐3β‐ol. This compound was referred to as M10 of 17α‐methyltestosterone in a literature. This finding highlights the potential discrepancies between product labeling and actual contents in the supplement market, which deserves attention from the anti‐doping community.