Due to Northern California power issues, AmiGO and related services may be running slow or be out of commission for the next few days. For up-to-the-date information, please see [status.geneontology.org] and [status.lbl.gov]. Our apologies for the disruption.
The action characteristic of a hormone, any substance formed in very small amounts in one specialized organ or group of cells and carried (sometimes in the bloodstream) to another organ or group of cells in the same organism, upon which it has a specific regulatory action. The term was originally applied to agents with a stimulatory physiological action in vertebrate animals (as opposed to a chalone, which has a depressant action). Usage is now extended to regulatory compounds in lower animals and plants, and to synthetic substances having comparable effects; all bind receptors and trigger some biological process. Source: GOC:dph, ISBN:0198506732, GOC:mah
Also consider annotating to 'receptor agonist activity ; GO:0048018'.