This is an interesting question which required some reading on my part. I found an a scholarly article in the Journal of Urology which addresses this question and concludes: “Profound suppression of circulating serum dihydrotestosterone induced by 5?-reductase inhibitors during 1 year does not adversely impact bone, serum lipoproteins or hemoglobin, and has a minimal, reversible effect on serum prostate specific antigen and sexual function in normal men. Circulating dihydrotestosterone does not appear to have a clinically significant role in modulating bone mass, hematopoiesis or lipid metabolism in normal men.?”?
The clinical doses for these drugs is relatively low so I believe that the article is discussing these low doses