Overall, the data do not support a causal connection between hormones and human sexual orientation. The large number of hypothetical neuro-endocrine mechanisms that must be considered in the search for an explanation of homosexuality makes it unlikely that a single mechanism underlies all forms of homosexuality. Efforts to measure the estrogen feedback as an indication of brain androgenization have produced inconsistent results. This review summarises the correlations between testosterone levels and male physical appearance and behaviour. Mean sex hormones were further tested in association to stress indices related to cortisol systemic output area under the curve with respect to ground based on ten measures throughout the two-hour visit, allostatic load indexed using 21 biomarkers, and perceived stress assessed using a well-validated questionnaire. Different kinds of behaviour are not only subject to influence by environment, but also androgens can reinforce the particular kind of conduct and the behavioural impact can wield negative or positive feedback on testosterone secretion. FSH and LH concentrations in plasma of 5 transsexual males were also significantly higher
Plasma basal levels of FSH, LH and testosterone in homosexual men.
Significantly lower free plasma testosterone was observed in 35 homosexual males Different kinds of behaviour are not only subject to influence by environment, but also androgens can reinforce the particular kind of conduct and the behavioural impact can wield negative or positive feedback on testosterone secretion. Our findings may be explained by the possible existence of a prenatal testicular androgen deficiency in homosexual males that is widely compensated by increased gonadotrophin secretion in adult life. Based on answers given to a questionnaire, subjects were assigned to one of five groups, ranging from exclusively heterosexual to exclusively homosexual. Efforts to measure the estrogen feedback as an indication of brain androgenization have produced inconsistent results.
Likewise, among sexual minority women compared to age-matched heterosexual controls, studies have reported lower estrogen Loraine et al. In summary, sex hormone variations appear to vary according to sexual orientation among women, but also as a function of cortisol systemic output, allostatic load, and perceived stress for both sexes. This chapter discusses the existing data on endocrine abnormalities—both in the prenatal and adult stage—in homosexual individuals as well as the evidence concerning sexual orientation in individuals with prenatal hormone disorders. This paper critically reviews the studies which explore a possible causal relationship between sex hormones and the development of sexual orientation. More recently, a theory that prenatal hormone levels produce varying degrees of brain androgenization and subsequent dimorphic sex role behavior has consistently been supported by studies in lower mammals.