The second highest concentration of iodine in the body is in the ovaries.
Iodine is essential for normal follicle development, progesterone production after ovulation, and protecting ovarian tissue from oxidative damage. When iodine is deficient — and most women in the modern world are — the thyroid and ovaries are competing for whatever's available. And the thyroid usually wins because the feedback loop for thyroid hormone is more tightly regulated.
Ovarian iodine deficiency shows up as estrogen dominance, irregular cycles, poor luteal phase (the post-ovulation phase where progesterone is supposed to rise and stay elevated for 10+ days), and cystic ovarian changes.
So whether you are looking at natural hormone support or hormone replacement therapy for with female hormone issues — If the iodine deficiency is driving the whole picture and hasn't been addressed you may be managing a system without the necessary structure to build upon.
So usually we are right with our symptoms, but the causes have to be slowly extracted using a variety of information our body gives us.