Hormonal IUDs, or coils, are different from all types of hormonal birth control in that they do not suppress ovulation and can, therefore, permit natural cycling.
Other benefits of hormonal IUDs are that they are convenient and a highly effective method of birth control. They can also dramatically reduce menstrual flow and relieve pain and other symptoms of endometriosis. Hormonal IUDs also have some downsides.
Pros of hormonal IUDs:
Unlike all other types of hormonal birth control, hormonal IUDs do not completely suppress ovulation–which is good because ovulation is how women make hormones. According to one study, Mirena suppresses ovulation in 85% of cycles during the first year (when the dose of the contraceptive drug is higher) and then in 15% of cycles after that. Some lower-dose IUDs may not suppress ovulation at all.
Compared to pills and implants, a hormonal IUD delivers a lower dose of a contraceptive drug. The blood level of levonorgestrel in Mirena users is about one-tenth of that 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%.
After insertion, you don’t need to do anything or take anything, and IUDs last 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, and there are concerns that long-term use could alter the uterine lining in ways that take time to reverse.
Hormonal IUDs reduce menstrual flow by at least 90%, a massive pro for heavy menstrual bleeding. Read: Natural treatment of heavy periods.
Hormonal IUDs can relieve some of the symptoms of endometriosis. For more endometriosis treatment ideas, see The hidden story of endometriosis.
Cons of hormonal IUDs:
Hormonal IUDs contain levonorgestrel, which is not progesterone and which affects the entire body, not just the uterus. Possible side effects of levonorgestrel include acne, hair loss, hirsutism, headaches, yeast infections, weight gain, breast changes, increased breast cancer risk, depression, and anxiety. (Interestingly, the copper IUD can also cause anxiety, which suggests that at least part of the anxiety response could be a physical response, such as an ongoing vagus nerve reaction.)
Some hormonal IUDs suppress ovulation some of the time.
Hormonal IUDs cause ovarian cysts in 5% of users.
Hormonal IUDs can damage the vaginal microbiome and increase the risk of yeast infections and bacterial vaginosis.
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 can be painful, and unfortunately, that pain was largely ignored until recently, when ACOG released new guidelines urging doctors to take pain seriously and routinely offer pain management, such as an anesthetic spray, topical numbing cream, or a paracervical block. It’s welcome news and long overdue.
Hormonal IUDs can come out. The chance of expulsion is 5%, but it is more likely immediately following childbirth and during breastfeeding.
Hormonal IUDs carry a small risk of uterine perforation, possibly leading to surgery. The chance of perforation is 0.1%, but it is more likely 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.
When you want it out, you’ll need a doctor to remove it.
Hormonal IUDs cannot protect against sexually transmitted infections.
Is it okay to suppress periods?
Hormonal IUDs suppress bleeding, which raises the question: “Is it okay not to 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 (or pregnancy), except in the case of a hormonal IUD, which permits ovulation but can suppress bleeding.
đź’ˇTip: With the pill, you bleed, but don’t cycle. With the hormonal IUD, you can cycle but not bleed
Next, read The pros and cons of copper IUDs.
