I've done a lot of reading as i didn't think I could have hrt as am still breastfeeding my youngest. (Turns out you can 🙄)
Lara briden describes ups and downs of oestrogen due to the way the cycle becomes more irregular and therefore sometimes not ovulating etc.
She sees the main point of a cycle as ovulation = best health. Overall over time it declines but there's ups and downs on the way. As progesterone is what thins the lining, women in early peri often describe heavy bleeding which is where I think she advocates to try progesterone first, favouring body identical. But essentially this is what the mirena is, which is often given to older women who bleed heavily.
Actually, I know a woman who has just been prescribed progesterone for heavy bleeding; Gp won't prescribe full hrt for some bizarre reason despite the facts she's 45.
The problem is that all women are different and over time the lack of oestrogen can be a big problem for bone, brain and heart health.
I then read the XXbrain by Lisa Misconi, who does recommend hrt, but talks a lot about diet, exercise and some vitamins as well. You can hear her discussing basics with Rupy Anjila on his podcast (fascinating stuff, eg post partum brain shrinkage!!)
So it's very possible that in early peri some women are lacking the progesterone, but it gradually moves on.
@RoseAddict you could try the other things that are suggested by Lara briden for now to support progesterone but it's possible you'll need more. I've read that women take ashwanga for this reason but the body gets used to it and the effect wears off. I used taurine a while ago and found it really helped sleep. Doesn't seem to be so effective now. But stress from work etc is much higher.
Ultimately it's a long game of tinkering with doses and methods and waiting 3 months.