Here is a tentative structure for THG. I am not 100% sure as the name tetrahydrogestrinone is not very specific. This is my best guess at the moment based on the structure of gestrinone. Gestrinone has relative binding affinities(RBA) for the progesterone receptor (PR) and androgen receptor (AR) of 76 and 83 versus progesterone and testosterone respectively. This means that gestrinone has roughly equal affinity for the PR and AR (a ratio of 1). Trenbolone, on the other hand has RBA's of 74 and 197 for the PR and AR respectively (a ratio of 2.67 AR:PR). I would guess that THG would have a profile similar to that of gestrinone (a ratio closer to 1) with possibly a little more AR affinity. This depends on the molecule being enzymatically converted to a 3-one in the body. If not, then you are left with a relatively less active diol.