Hi shellb
I can't remember if you are still peri or post meno now?
if you are still peri then it is very difficult to say what is doing what ie whether it is the change in dose of Utrogestan or your own natural hormones. Once you are two years post-menop things become more predictable so easier to experiment and know what is causing any changes in mood or symptoms!
Also sorry I can't remember if you take it vaginally or orally - if orally then the amount getting into your system can vary depending on your own digestion etc as it is a very unstable compound.
It is very unlikely that increasing progesterone could cause improvements in mood and decrease cause anxiety, since progesterone is a mood dampener - it is a sedative, and these effects are more pronounced at higher doses. However for a few days following the decrease from 200 mg to 100 mg you could experience progesterone withdrawal symptoms - similar to pmt until your bidy stabilised at the lower level, and then you would experience this again when you stopped at 25 days.
Could your own cycle be coming into play? What about the oestrogen dose you are taking? Maybe you could try increasing this?
I would suggest trying it like this for another couple of months to see if your body settles, and if not think about changing the oestrogen dose or going back to a proper cycle.
I sympathise because it is hard to actual settle permanently on a regime during peri-menopause (if you are) because of your own hormones. Sorry this isn't much help! Hopefully others in the Utrogestan gang will have something to say too!
Hurdity x