They release progestin, not estrogen. And even then they seem to release a 3-7x lower volume of hormones per day than pills.
I also would ask for a source on the relative popularity of the hormonal IUDs vs the non-hormonal copper ones; I haven't seen any source provide that sort of breakdown.
I also would ask for a source on the relative popularity of the hormonal IUDs vs the non-hormonal copper ones; I haven't seen any source provide that sort of breakdown.