The document discusses DT56a (Femarelle), a natural compound that acts as a selective estrogen receptor modulator (SERM). It activates estrogen receptors in osteoblasts, relieves menopausal symptoms, and increases bone mineral density without affecting sex hormone or endometrial thickness levels. Studies in rats and human cells found that while DT56a and estradiol-17beta (E2) both stimulate creatine kinase in skeletal and vascular tissues, only E2 did so in the uterus. When administered together at high doses, DT56a inhibited or partially inhibited E2's effects in various rat and human tissues, demonstrating that DT56a is a SERM that has tissue-specific estro