well said StellaJane, it all seems to be a balancing effect too, too much or too little prog may lead to anxiety/depression, as in oestrogen, as many people have stated the utrogestan/progestrone may reach too high a level in some people, esp with the prescribing amounts recommended by NICE. On oestrogen alone, once I got used to the dose, that was the only thing that was still lacking, just a slight increase in mood (never been depressed before) and that amount of prog (so far) seems to be OK.
Rhiner