Both the adrenal and the ovary contain the biosynthetic pathways necessary for androgen synthesis and secretion. The fetal ovary is not very active but the fetal adrenal is an important source of DHAS. However the secretion of DHAS declines markedly after birth and until puberty there is little androgen secretion by either the adrenal or the ovary. Post-pubertally, the adrenal secretes DHAS, DHA, delta 4-A and T from the reticularis and probably the fasciculata. This secretion is under ACTH control, at least in part, but apparently also under control of another pituitary polypeptide tentatively called 'adrenal androgen secretory hormone'. THe adrenal secretion rates are in the range of 7-14 mg/day for DHAS, 3-4 mg/day for DHA, 1-1.5 mg/day for delta 4-A and 50 micrograms/day for T. Androgen secretion from the ovary arises in part from the theca cells of the follicle, the corpus luteum and the stromal cells, under LH control, and will vary somewhat during the normal menstrual cycle. The ovarian secretion rate in the follicular phase is 1-2 mg/day for DHA, 1-1.5 mg/day for delta 4-A and about 50 micrograms/day for T. In the peri-ovulatory period the secretion rate of delta 4-A can rise to 3-3.5 mg/day but there appears to be little change in the secretion of DHA and T. The normal ovary does not secrete significant amounts of DHAS. In about 50% of post-menopausal women the ovaries continue to secrete some T but little delta 4-A or DHA.