The results clearly indicate that androsterone (ADT, chemical structure on the left; source: HMDB: Androsterone), a potent neurosteroid, some "bros" misunderstand as a precursor or pro-hormone to testosterone and estrogen (actually it is a testosterone metabolite), has a regulative effect on sexual function in men.
The scientists measured cerebrospinal fluid (CSF) levels of several steroids and monoamine metabolites and found low androsterone levels to be the major correlate of decreased sexual desire:
"...the change in CSF androsterone levels was correlated with the change in the severity of decreased sexual interest between testosterone-replaced and hypogonadal conditions (r=−0.68; P<.05)."In this context the following table, summarizing the correlation of ADT, DHT and T and selected symptoms of hypogonadism in the course of the three stages the participants of the study have undergone, may be of particular interest for all of you on prescribed (or self-prescribed) testosterone replacement (cf. Bloch. 2006. Table 3)
*Just a note on how to read this table: A correlation of 1.0 means maximum positive correlation and would support the hypothesis that there certainly is a relationship between the symptom on the left and high levels of the respective hormone in the first row of the table. A negative correlation of -0.11, on the other hand, suggests that there is a chance that an increase in the respective hormone will alleviate the symptom listed in the left column.
As a side note: In view of the fact that Dehennin et.al. (Dehennin. 1998) identified "androsterone, and etiocholanolone as the most abundant metabolites" of DHEA in healthy men, it is no wonder that DHEA supplementation is known for its beneficial effects on sexual desire and function.