Androstadienol
[1][2] Androstadienol and androstadienone are odorless compounds secreted by the apocrine glands, and via conversion into the more powerfully-odorous androstenone and androstenol (catalyzed by aerobic corynebacteria, particularly Corynebacterium xerosis, in men, and Micrococcaceae spp.in women), are considered to be mainly responsible for the "musky" component of axillary (underarm) odor.[1][2] Androstadienone, which is produced from androstadienol, has been found to affect brain activity.[6] Specifically, it has been found to activate the hypothalamus, most maximally the medial preoptic and anterior hypothalamic areas, in heterosexual women and homosexual men, but not in heterosexual men (who instead experienced hypothalamic activation in response to smelling estratetraenol, an estrogen-related pheromone, while heterosexual women and homosexual men did not).[6] The affected brain areas are thought to be involved in sexual behavior, attention, visual perception/recognition, and social cognition.