3β-Hydroxytibolone
3β-Hydroxytibolone is a synthetic steroidal estrogen which was never marketed. Along with 3α-hydroxytibolone and δ4-tibolone, it is a major active metabolite of tibolone, and 3α-hydroxytibolone and 3β-hydroxytibolone are thought to be responsible for the estrogenic activity of tibolone.