Contribution of dihydrotestosterone to male sexual behaviour

Abstract

Objective: To document the relative importance of endogenous sex steroids in modulating the frequency of orgasms, the dominant aspect of sexual behaviour in healthy eugonadal men. Design: Measurement of adrenal and testicular sex steroids in a sample of army recruits and study of their relation to frequency of orgasms ascertained by questionnaire after potential confounding variables were controlled for. Setting: Military campus and military hospital laboratories in Athens, Greece. Subjects: 92 consecutively enrolled healthy male recruits aged 18-22 years. Main outcome measures: Weekly number of orgasms. Serum concentrations of testosterone, dehydroepiandrosterone sulphate, dihydrotestosterone, oestradiol, oestrone, δ-4-androstenedione, and sex hormone binding globulin. Results: Serum dihydrotestosterone concentration was the only independent hormonal predictor of the frequency of orgasms; an increase in concentration of 1.36 nmol/l (about 2 SD) corresponded to an average increase of one orgasm a week. Conclusions: Differences in concentrations of circulating dihydrotestosterone within the normal range may represent a major predictor of sexual activity in healthy young men. Key messages The hormone that determines sexual behavior has not yet been conclusively identified in healthy adults This study shows that dihydrotestosterone is the dominant hormonal determinant of the frequency of orgasms in young healthy adults The frequency of orgasms depends not only on psychosocial factors but on variation of dihydrotestosterone concentrations within the normal range