selective estrogen receptor modulator

Selective estrogen receptor modulators (SERMs) are a class of medication that acts on the estrogen receptor. A characteristic that distinguishes these substances from pure receptor agonists and antagonists is that their action is different in various tissues, thereby granting the possibility to selectively inhibit or stimulate estrogen-like action in various tissues.
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Se·lec·tive estrogen receptor modulator n. Abbr. SERM A nonsteroidal compound, such as raloxifene or tamoxifen, designed to mimic the effect of [more]Selective estrogen receptor modulator - Community and Resources

A "designer estrogen" which possesses some, but not all, of the actions of estrogen. For example, raloxifene (trade name EVISTA) is classified as a SERM because it prevents bone loss (like estrogen) and lowers serum cholesterol (like estrogen) but (unlike estrogen) does not stimulate the endometrial lining of the uterus.

[sel-EK-tiv ESS-tro-jen re-SEP-tor MOD-yew-lay-tor]
SERM. A drug that acts like estrogen on some tissues but blocks the effect of estrogen on other tissues. Tamoxifen and raloxifene are SERMs.