Encyclopedia of Behavioral Medicine

Living Edition
| Editors: Marc Gellman


  • Yori GidronEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-1-4614-6439-6_1354-2


An agonist is any molecule which binds to a receptor on a cell, which then can potentially lead to subsequent changes in the cell’s functions. While agonists activate or trigger a process that follows their binding to a receptor, an antagonist inhibits these effects, and an inverse agonist results in opposite effects to those of the agonist. In pharmacology, this issue is pivotal, as certain medications can act as agonists of receptors, where they mimic the effects of a natural compound or ligand that normally binds to the same receptor. However, the synthetic compound can possibly lead to similar cellular changes without unwanted side effects or to compensate for a deficiency in the natural ligand. Indeed, receptors can be activated by endogenous agonists – a natural compound which binds to a receptor. In contrast, receptors can also be activated by exogenous agonists – synthetic medications or compounds which activate a receptor. An example of an endogenous agonist is...

This is a preview of subscription content, log in to check access.

References and Further Readings

  1. Goodman, L. S., Gilman, A., & Brunton, L. L. (2008). Goodman and Gilman’s manual of pharmacology and therapeutics (11th ed., p. 14). New York: McGraw-Hill Medical.Google Scholar
  2. Hodges, L. C., Cook, J. D., Lobenhofer, E. K., Li, L., Bennett, L., Bushel, P. R., et al. (2003). Tamoxifen functions as a molecular agonist inducing cell cycle-associated genes in breast cancer cells. Molecular Cancer Research, 1, 300–311.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.SCALabLille 3 University and Siric OncollileLilleFrance