The only thing I can add to this is if your SHBG is low then you may find your libido better at lower then 20 say between 15 to 20 pg/ml. I have found the best way to tell is to take Indolplex/DIM or Arimidex with the DIM one tablet at dinner with the Arimidex .25mgs every 3 days. In less then 10 days you will get some strong morning wood this to me is when you have your E2 in the zone. I stay on this but if wood stops to me it means my E2 is going down to low. So I stop taking the stuff until the wood comes back that day I go back on it but do less.