The thing about progesterone is that it does deplete during peri-menopause in that this is when anovulatory cycles occur. Oestrogen then allows the uterus lining to build up leading to heavy and sporadic bleeding, so progesterone alone can be given in order to regulate periods and protect the womb from build up. As women get further towards menopause then oestrogen declines overall even while still fluctuating so oestrogen replacement prevents that crash which can occur either just after mid cycle (if ovulation occurs) but especially towards the latter part of the cycle and first part of the next cycle ie provides a buffer against the fluctuations when oestrogen falls very low.
I haven't looked at the research papers recently but I am sure studies into symptoms have looked at oestrogen and progesterone replacement both during peri-menopause and post-menopause.
It is acknowledged by some specialists that a small minority of women may benefit from progesterone replacement to alleviate symptoms but this is a minority. Studies show that most of us benefit overall from oestrogen repalcement along with progesterone to protect the womb lining.
Progesterone cream is not licensed as part of HRT because it does not provide sufficient progesterone to protect the womb and compounded progesterone because it is non-standard and unregulated so it is not possible to determine what dose you are getting whereas the approved stuff is regulated. GPs do not have progesterone cream at their disposal because there is no licensed product. I doubt you will find BMS approved menopause specialists recommending it either for the same reasons.
Someone told me about Prof Jerilyn Prior ( https://www.cemcor.ubc.ca/media/prior_bio ) who also advocates a progesterone only approach. It seems that there is quite a way to go before this is accepted more widely without controversy though
It's not a controversy as such - as I said - just lacks a regulated product and as far as I know, insufficient evidence base to warrant investment maybe? Obviously all sorts of weak products can be purchased privately at great expense and at your own risk or off the shelf - even weaker and anyone who wants to try them is welcome.
Me - I prefer to use something that is tried and tested properly with regulated trials as a starting point - even if one then deviates from the licensed regime to some extent as I do ( under medical supervision).
There is also nothing to stop anyone from cutting patches to give a very small oestrogen dose and eg taking progesterone every couple of days to protect the womb - if doc approves....
Hurdity x