I was looking online and I found this info on Mirena
Levonorgestrel is a progestogen. The contraceptive and therapeutic effects of Mirena are mainly based on local progestogenic effects in the uterine cavity. Levonorgestrel has an antiproliferative effect on the endometrium and it inhibits the endometrial synthesis of estrogen receptors, making the endometrium insensitive to the circulating estradiol. Morphological changes of the endometrium and a weak local foreign body reaction are observed during use of Mirena.
So my question is that if it "inhibits the endometrial synthesis of estrogen receptors" in the uterus, and we know that the progestin travels around the body could it "inhibits the ....... synthesis of estrogen receptors" in other parts such as the brain?
Maybe this could explain the recovery times ie how long it takes our body to increase estrogen receptors again?