I have same problem. As I entered my 40's it got worse and worse. I had an ultrasound and it showed I had a uterine polyp. So I went in for surgery to have the polyps removed. the first period after surgery was sooo much lighter!!! Then the next month it was back to being heavy again!!!!! ughhhhhhh.
I was prescribed tranexemic acid and I can't take it because the pills are way too big!!! At one point my iron went down to 9.6. I was a complete wreck!
I just take iron pills here and there and I seem to be okay. I tried figuring out how much blood I use based on tampon/pad use and I came up with somewhere between 300 and 400 ml. I use a super plus tampon and pad at same time. and on the first day I am changing the tampon every hour or less! I can soak it in about 30 minutes!

Periods are still regular, may be a day shorter too.