"As an example of the relative binding affinities of androgens to the progesterone receptor (PR), if progesterone itself is given an arbitrary relative binding affinity (RBA) of 100, testosterone's RBA is 1.1; DHT's is 0.9; nandrolone's RBA is 20; trenbolone's is 60 (2)"
Just today I read a different article that also said tren has 3 times the progesterone affinity as nandrolone. Interesting coincidence. Wow, tren has 60% the binding affinity as straight progesterone... No wonder I have to use dostinex