Metabolism of boldenone in man: Gas chromatographic/mass spectrometric identification of urinary excreted metabolites and determination of excretion rates
Wilhelm Schänzer; Manfred Donike
Biological Mass Spectrometry1992
Summary (paraphrased)
The foundational human metabolism study of boldenone: using GC/MS, the authors identified the urinary metabolites of boldenone administration, quantified excretion rates, and characterized the 5α- and 5β-reduced metabolites — the pathways through which dihydroboldenone arises and is cleared as conjugates. It establishes that boldenone-series steroids undergo extensive reductive metabolism with urinary excretion as conjugated metabolites. For Powers' model, it documents the metabolic plumbing: DHB is cleared not as parent drug but as reduced, conjugated metabolites — exactly the pool his glucuronidation-defect hypothesis concerns.
Why it’s in the systems review
Powers' glucuronidation-defect model is specifically about metabolite clearance: DHB "stacks as metabolites" only if reductive metabolism plus conjugation is the clearance route, and this study proves exactly that for the boldenone series in humans. It identifies which reduced metabolites form and how they are excreted, giving the corpus a concrete metabolic map against which UGT2BXX-deletion claims can be evaluated. It is the metabolic companion to Friedel 2006's pharmacology.