Estrogen agonist/antagonist properties

Mueller SO, Simon S, Chae K, Metzler M, Korach KS. Phytoestrogens and their human metabolites show distinct agonistic and antagonistic properties on estrogen receptor (alpha) and ER(beta) in human cells. Toxicol ScL 81, 530-531, 2004. 

Antiestrogen estrogen receptor antagonist downregulates estrogen receptor protein in human breast cancer cells no estrogen agonist properties... 

Selective estrogen receptor modulators (SERMs) are synthetic compounds with partially agonistic and partially antagonistic estrogenic properties. In bone, SERMs inhibit bone resorption via the mechanisms known for estrogens. Major SERMs are tamoxifen, a triphenylethylene compound, and raloxifene. In postmenopausal women, the latter has been shown to prevent bone loss and to reduce fracture risk by 40%. 

Effects on sexual behaviour should be considered adverse. Testing of sexual behaviour is not usually available and not warranted in all cases, but should be considered for those agents that cause neurotoxicity and those that have agonistic or antagonistic adrenergic or estrogenic properties. 

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