Can low DHEA-S after menopause reduce overall sex-hormone bioavailability?

An evidence-based assessment of the role of adrenal precursors in postmenopausal sex steroid synthesis reveals key mechanistic insights:

Clinical and physiological evidence

• Shift to Adrenal Precursors: Following the decline of ovarian estradiol production during menopause, the body relies almost exclusively on circulating adrenal androgens—principally dehydroepiandrosterone (DHEA) and its sulfated form (DHEA-S)—to maintain peripheral steroidogenesis.
• Depletion of the Precursor Pool: Because these adrenal androgens serve as the essential starting material for local hormone synthesis, low DHEA-S levels severely restrict the substrate pool. Under conditions of stable or high sex hormone-binding globulin (SHBG), this depletion directly limits the synthesis and subsequent bioavailability of free testosterone and estradiol, leading to downstream clinical signs such as reduced bone mineral density, low libido, and vaginal atrophy.

Mechanistic explanations

• Local Intracrinology: Peripheral tissues (such as bone, adipose tissue, and the vaginal epithelium) possess the required enzymatic machinery—including steroid sulfatase (STS), 3$\beta$-hydroxysteroid dehydrogenase ($3\beta$-HSD), and aromatase—to independently convert circulating DHEA-S into active estrogens and androgens.
• Intracellular Inactivation: Once converted, these active hormones act locally within the cells and are metabolized into inactive forms before re-entering systemic circulation, minimizing systemic side effects while supporting tissue-specific requirements.

Bottom line

In postmenopausal women, adrenal DHEA-S acts as the primary precursor pool for local sex steroid production. Low levels of DHEA-S limit this intracrine pathway, reducing overall bioavailable sex hormones and worsening symptoms of estrogen and androgen deficiency.