Elacestrant

Elacestrant is a selective estrogen receptor degrader (SERD) and selective estrogen receptor modulator (SERM) hybrid. It binds to estrogen receptors and causes them to be degraded into their constituent amino acids through the normal protein degradation process. Unlike other SERDs such as fulvestrant, its effects appear to be tissue-specific: it does not cause bone loss even in the absence of estradiol, so it presumably does not degrade estrogen receptors in bone and actually acts as an estrogen receptor agonist. On the other hand, it degrades ERα in breast tissue and prevents the proliferation of uterine tissue, presumably through the same mechanism.

Elacestrant has a different mechanism of action than other SERMs such as raloxifene or tamoxifen. It actually destroys the estrogen receptor in some tissue rather than simply binding to it.

Unlike raloxifene, it is not known if elacestrant has any outwardly visible feminizing effects.