The androgens testosterone and dihydrotestosterone (DHT) are essential for a variety ofsystemic functions in mature males. Alteration of these hormones results in late-onset hypogonadism(LOH) and benign prostate hyperplasia (BPH). The fruit bodies of fungi of the genus Cordycepshave been regarded as folk medicine or health food with tonic and antifatigue effects. The extractfrom the fruit body of Cordyceps militaris parasitizing Samia cynthia ricini (CM) was evaluated asa novel-candidate natural product for ameliorating male andropause symptoms. To explore theeffects of CM on LOH and BPH, CM was applied to rat models and cultured testicular cells andprostate cells. The concentrations of androgens in the serum and culture media were determined byELISA. Expression of steroidogenic enzymes and androgen-related genes was evaluated by qPCR,and prostatic cell proliferation was assessed with the cell-viability assay. CM maintained the serumlevels of testosterone and DHT, but inhibited testosterone-induced prostate hypertrophy. CM alsoincreased the secretion of testosterone and DHT by primary testicular cells, with no changes inthe mRNA expression of steroidogenic enzymes, but decreased the growth of prostatic cell lines.Our data suggest that CM could improve both LOH and BPH in males