Cholesterol is the precursor for five major classes of steroid hormones: progestagens, glucocorticoids, mineralcorticoids, androgens, and estrogens. These hormones are powerful signaling molecules that are released in order to elicit a specific response.
Androgens, such as testosterone, are responsible for the development of male sex characteristics, whereas estrogens are responsible for the development of female sex characteristics. Dehydroepiandrosterone (DHEA) is the most abundant circulating steroid in humans, and is a precursor for the sex hormones, testerosterone and estradiol. In addition, DHEA is a cortisol antagonist.
Glucocorticoids, such as cortisol, promote the formation of glycogen and inhibit the inflammatory response. They enable humans (and animals) to respond to stress.
Steroids act by interaction with cellular receptors that serve as transcription factors to regulate gene expression. Steroids are incredibly potent and elicit very specific responses due to their interaction with steroid receptors.