See Designer estrogens. Synthetic Hormones: Refers to hormones created in the lab to be molecularly similar to the endogenous human hormones, but having changes in their structure which allows them to be patented, among other things. This alteration is necessary since no natural substance, or molecular copy of a natural substance, may be patented in the US.

(selective estrogen receptor modulator): a family of drugs for use in preventing osteoporosis in postmenopausal women. SERMs act like estrogen in some tissues, while at other times blocking the effects of estrogen. That is why they are said to be selective