[{"from": "human", "value": "Please give me some details about this molecule. [C][C][Branch2][Ring2][Ring1][C][=C][Branch2][Ring1][Branch1][C][=C][C][=Branch1][Ring2][=C][Ring1][=Branch1][C][=C][C][=C][Branch1][Branch1][N][Ring1][Branch1][C][C][#N][N][C][=Branch1][C][=S][O][Ring2][Ring1][Ring1][C]"}, {"from": "gpt", "value": "The molecule is an investigational non-steroidal progestin. It is a high affinity, high efficacy agonist of the progesterone receptor (PR) with a much more selective binding profile relative to most conventional progestins. Because of this tanaproget may prove to produce fewer side effects in comparison. It is currently in the process of being developed for clinical use as a contraceptive by Ligand Pharmaceuticals. An analog of tanaproget, 4-fluoropropyltanaproget (18F), has been developed as a radiotracer for imaging of the PR in positron emission tomography."}]