Does low DHEA-S reduce androgen substrate availability in postmenopausal women?

Dehydroepiandrosterone sulfate (DHEA-S) represents a cornerstone of the human steroidome, particularly as women transition through and beyond menopause. As ovarian follicular activity ceases, the body shifts its reliance for sex steroid production to a system of local synthesis fueled by circulating adrenal precursors.

Mechanisms of production and conversion

DHEA-S is almost exclusively produced in the zona reticularis of the adrenal cortex. This tissue-specific production is driven by the high expression of the enzyme SULT2A1, which sulfates DHEA into its more stable, circulating form.

• The Prohormone Reservoir: DHEA-S acts as a massive reservoir, with circulating levels significantly higher than other steroids. Its long half-life allows it to reach peripheral tissues where it is converted into active androgens.
• Intracrine Cascade: In peripheral tissues such as the skin, bone, and vaginal wall, the enzyme steroid sulfatase (STS) converts DHEA-S back into DHEA. A sequence of enzymes (3βHSD, 17βHSD, and 5α-reductase) then transforms this precursor into testosterone and ultimately dihydrotestosterone (DHT), the most potent androgen.

Clinical implications for postmenopausal women

For a 73-year-old woman, the adrenal contribution to the androgen pool is critical because the ovaries no longer produce significant estrogens, though they may still secrete some testosterone.

• Adrenopause and Substrate Availability: DHEA-S levels decline by approximately 80% between the ages of 20 and 70. This decline, known as adrenopause, directly reduces the raw material available for peripheral tissues to synthesize their own androgens.
• Androgen Buffering: While low DHEA-S reduces substrate availability, the impact on total androgenic activity is not always linear. Some women maintain androgen levels through continued ovarian secretion of testosterone or via the 11-oxygenated androgen pathway, an alternative adrenal route that does not rely on DHEA-S and remains relatively stable with age.

Bottom line

The adrenal glands are the primary source of DHEA-S, which serves as the essential raw material for peripheral androgen synthesis. In postmenopausal women, a decline in DHEA-S directly limits the substrate available for conversion into testosterone and DHT, although individual androgen status may be partially sustained by residual ovarian function and alternative adrenal pathways.