The effects of autacoids are primarily local, though large quantities can be produced and moved into circulation.
Autacoids can have a variety of different biological actions, including modulating the activities of smooth muscles, glands, nerves, platelets and other tissues.
[citation needed] Some autacoids are chiefly characterized by the effect they have on specific tissues, such as smooth muscle.
Some notable autacoids are: eicosanoids, angiotensin, neurotensin, NO (nitric oxide), kinins, histamine, serotonin, endothelins and palmitoylethanolamide.
In 2015, a more precise definition of autacoids was proposed: "An autacoid is a locally produced modulating factor, influencing locally the function of cells and/or tissues, which is produced on demand and which subsequently is metabolized in the same cells and/or tissues".