DHEA-S, or dehydroepiandrosterone sulfate, is a hormone produced by the adrenal glands, which are located on top of the kidneys. It's a sulfated form of the hormone dehydroepiandrosterone (DHEA). DHEA-S is the most abundant circulating steroid hormone in the human body.

DHEA-S plays several important roles in the body:

Precursor to Other Hormones: DHEA-S can be converted into other hormones, including both androgens (male sex hormones) and estrogens (female sex hormones). This conversion can occur in various tissues, allowing DHEA-S to influence a wide range of physiological processes.

Aging and Stress: DHEA-S levels tend to peak in the body during young adulthood and then decline with age. Some research suggests that DHEA-S may be involved in the aging process and could play a role in maintaining overall health and well-being.

Immune Function: DHEA-S may have immunomodulatory effects, potentially influencing the body's immune response to infections and other health challenges.

Energy and Mood: Some individuals take DHEA supplements in the belief that it can improve energy levels and mood, although scientific evidence for these claims is limited and mixed.

Overall, DHEA-S is a multifunctional hormone with various potential effects on the body. Its levels can be measured in blood tests and may be relevant in the diagnosis and management of certain medical conditions, such as adrenal disorders or hormonal imbalances. However, the use of DHEA supplements should be approached with caution and under medical supervision, as its effects can vary widely among individuals and may have side effects.