Hormones [Chemical/Ingredient] Hormone C291528 M0010538 C0019932 Hormones 5436 N0000011172 Hormones Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects. D006728 Hormones, Hormone Substitutes, and Hormone Antagonists [Chemical/Ingredient]