Estren is a steroid ligand that exhibits lower binding affinity for estrogen receptor and has no classical transcriptional activity. Estren has been shown to attenuate osteoblast apoptosis, stimulate osteoclast apoptosis, and increase bone mass and strength with no affect to reproductive organs in a non-sex-specific mechanism of action. Estren is possibly useful in studies pertaining to hormone replacement therapy for osteoporosis.
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