Dehydroepiandrosterone sulfate (DHEA-S) is a sulfated steroid hormone, specifically the 3β-sulfate ester of dehydroepiandrosterone (DHEA). It is a major circulating form of DHEA, produced primarily by the adrenal cortex. DHEA-S serves as a stable precursor and reservoir for the active hormone DHEA and downstream androgens and estrogens. Clinically, DHEA-S is a crucial biomarker for assessing adrenal function. Its measurement is standard in the diagnosis of conditions such as adrenal tumors, congenital adrenal hyperplasia (CAH), and adrenal insufficiency. As an active pharmaceutical ingredient (API), it is investigated for therapeutic applications related to hormone replacement, aging, and certain autoimmune conditions, placing it within the endocrine and metabolic drugs category. From a biochemical perspective, DHEA-S is a key intermediate in steroidogenesis. It is classified as a sterol or steroid derivative, a core class within lipid biochemistry. Its role as a prohormone and its significance in endocrine research make it a fundamental biological chemical for life science studies.