Hormonal IUDs are different from all types of hormonal birth control in that they do not suppress ovulation and therefore can permit natural cycling.
Other benefits of hormonal IUDs are that they can dramatically decrease menstrual flow and relieve symptoms of endometriosis.
Pros of hormonal IUDs:
Unlike all other types of hormonal birth control, hormonal IUDs do not completely suppress ovulation and ovarian hormones. According to one study, Mirena suppresses ovulation in 85 percent of cycles during the first year (when the dose of the levonorgestrel drug is higher), and then in 15 percent of cycles after that. Lower dose IUDs permit ovulation more of the time. Because hormonal IUDs permit ovulation at least some of the time, they are probably the best option of all types of hormonal birth control.
Tip: Ovulation is beneficial because it’s how women make hormones.
Compared to pills and implants, hormonal IUD delivers a lower dose of a contraceptive drug. The blood level of levonorgestrel in Mirena-users is about one-tenth of pill-users. Unfortunately, even that low dose can cause side effects (see below).
Hormonal IUDs are more effective than almost any other method of contraception, with a failure rate of just 0.7 percent.
After insertion, you don’t need to do anything or take anything, and IUDs lasts three years (Skyla) or five years (Mirena).
In theory, fertility returns to normal almost as soon as a hormonal IUD is removed. (In practice, it can take a little longer.)
Hormonal IUDs reduce menstrual flow by at least 90 percent, and that’s a huge pro for heavy menstrual bleeding. (Also read Diet and natural progesterone for heavy periods.)
Hormonal IUDs can relieve some of the symptoms of endometriosis. For other endometriosis treatment ideas. (Also read Immune treatment for endometriosis).
Cons of the hormonal IUD:
Hormonal IUDs release the contraceptive drug levonorgestrel, which is not progesterone. Side effects of levonorgestrel include acne, hair loss, hirsutism, depression, anxiety, headaches, breast pain, yeast infections, weight gain, and anxiety. (Interestingly, anxiety is also reported by some women with the copper IUD which suggests the anxiety could be the result of something else such as a vagal nerve response to the IUD or the string.)
Hormonal IUDs cause ovarian cysts in 5 percent of users.
Hormonal IUDs can damage the vaginal microbiome and increase the risk of yeast infections and bacterial vaginosis.
Hormonal IUDs suppresses ovulation some of the time.
Hormonal IUDs can cause irregular bleeding and spotting during the first three to six months of use. After that, they may suppress bleeding entirely or permit a light natural menstrual period.
Insertion might be painful. But just to clarify: IUD is an in-office procedure that takes just a few minutes—it’s not surgery. You’ll probably be instructed to take a painkiller like ibuprofen to ease the cramping, or your doctor may decide to use a local anesthetic (or more rarely, a general anesthetic ).
Hormonal IUDs can come out. The chance of expulsion is 5 percent but more likely immediately following childbirth and during breastfeeding.
Hormonal IUDs carry a small risk of uterine perforation, which could lead to surgery. The chance of perforation is 0.1 percent but more likely if during breastfeeding.
Hormonal IUDs can cause pelvic inflammatory disease (PID) but only during the first three weeks after insertion, and only if you have a pre-existing infection with gonorrhea or chlamydia.
Hormonal IUDs must be removed by a doctor. See my copper IUD post for more information about IUD removal.
Hormonal IUDs cannot protect against sexually transmitted infections.
Is it okay to suppress periods?
Hormonal IUDs suppress bleeding, which inevitably raises the question: “Is it okay to not have a period?”
There’s no medical reason to bleed monthly, and certainly, no reason to bleed monthly on the pill because pill-bleeds are not periods.
There is, however, a reason to ovulate monthly because ovulation is how women make hormones. Normally, ovulation leads to a bleed, except in the case of a hormonal IUD, which permits ovulation but can suppress bleeding.
Tip: With the pill, you bleed but don’t cycle. With the hormonal IUD, you can cycle but not bleed.