IUD Mirena Insurance And Side Effects

Are you having a good weekend? Today I will organize, all at once, the basic principle of the intrauterine device (IUD), its representative side effects, and the insurance-coverage issue that many are curious about. In the clinic, not a few think that "loop," "Mirena," and "copper IUD" are all the same thing, but in fact these differ in mode of action and in the changes that appear in the body. To judge which device suits your body, it helps to first understand how the IUD prevents pregnancy and what changes it makes.

The intrauterine device is a device placed inside the uterus to maintain a contraceptive effect for a long time, and it is divided largely into two families. One is the copper IUD wound with copper, and the other is the hormonal intrauterine system (LNG-IUS), which slowly releases the corpus luteum hormone (levonorgestrel). Names like Mirena, Kyleena, and Jaydess all belong to the latter, that is, the hormonal family.

The two families differ in mode of action and suitable candidates as follows.

• The copper IUD contains no hormones, so it becomes an option for those who want to avoid hormone use or are breastfeeding.
• The hormonal IUS has only a small amount of corpus luteum hormone acting locally in the uterus, so its systemic hormonal influence is relatively small, and treatment of heavy menstruation or menstrual pain can also be expected from it.

Which family is suitable depends on whether contraception alone is the purpose or symptom treatment is also wanted. If you are curious about the overall options of contraceptive methods, it is good to first read the article organizing what types of contraception there are.

The core of the hormonal IUS is the corpus luteum hormone released locally in the uterus. This hormone acts on the endometrium at a constant daily dose and makes the establishment of pregnancy difficult at several stages.

First, it changes the cervical mucus to be sticky, making it hard for sperm to enter the uterus. Second, it suppresses the proliferation of the endometrium and keeps it thin. According to the UK Faculty of Sexual and Reproductive Healthcare (FSRH, 2023), the hormonal IUS has little effect on the hypothalamic-pituitary-ovarian axis, so in most users ovulation is maintained and the blood estrogen level does not drop greatly. That is, it works not in a way that shakes the whole body but in a way that changes sperm entry and the endometrial environment locally in the uterus.

Because of this principle, the hormonal IUS is used beyond simple contraception, for the therapeutic purpose of protecting the endometrium.

The copper IUD produces a contraceptive effect by the action of copper ions, without using hormones. The FSRH (2023) explains that the main contraceptive mechanism of the copper IUD lies in preventing fertilization itself. Copper ions affect the motility and viability of sperm, and also act on the movement and viability of the egg, making fertilization hard to occur.

For those sensitive to hormones or wanting to avoid hormone use, and those breastfeeding, the copper IUD can be one option. However, the copper IUD does not reduce menstrual volume and is rather reported to increase menstrual volume early on or add menstrual pain. So for those who usually have heavy menstruation or severe menstrual pain, the hormonal IUS is often more suitable. For those with menstrual pain or frequent irregular periods, examining the cause first helps with the choice.

The intrauterine device, even among long-acting reversible contraceptive methods, is in the very-high-effectiveness category. ACOG (American College of Obstetricians and Gynecologists, 2017) summarizes that both the hormonal IUD and the copper IUD have a pregnancy-prevention effect exceeding 99%, with no meaningful difference in effect between the two families. The FSRH (2023) likewise reports the first-year failure rate as low, at roughly under 1%.

The reason effectiveness is this high is that, unlike the oral contraceptive that must be attended to daily, once placed it maintains its effect for several years without the user's effort. ACOG (2017) also counts as an advantage the point that the IUD's effect is not easily shaken by weight, body mass index, or some drugs. However, since expulsion, in which the device comes out or its position changes after placement, is reported at a certain rate in the first year, regular position checks are needed.

If, along with contraception, the possibility of pregnancy itself worries you, we can check it together in the clinic.

The intrauterine device is used relatively safely, but in the early period after placement, various changes can appear as the body adapts. Organizing the patterns often heard in the clinic in a table is as follows.

In the case of the hormonal IUS, spotting or abnormal bleeding increases in the early period after placement, then, in pooled analyses of several studies, the number of bleeding days is reported to decrease to the pre-placement level after several months of use. As the period of use lengthens, amenorrhea, in which menstruation itself almost disappears, may appear, but this is an expected change from the endometrium thinning, not something accumulating in the body. If such bleeding changes worry you, the article on how far you can observe bleeding after placement may help.

The above symptoms may not appear at all in some cases, and the degree and frequency vary from person to person. There is no need to fear side effects excessively in advance, but if pain worsens, or there is fever or sudden heavy bleeding, it is safer to get medical care.

The hormonal IUS is not a device for contraception alone. Thanks to its property of suppressing the proliferation of the endometrium, it is also used in the treatment of various gynecological diseases. In clinical experience, the hormonal IUS is applied to menstrual pain severe enough to make daily life difficult, heavy menstruation, adenomyosis, endometrial hyperplasia, and the purpose of protecting the endometrium in post-menopausal hormone therapy.

The evidence is also relatively solid. The hormonal IUS is reported to reduce bleeding volume in heavy menstruation and ease menstrual pain, and in some clinical guidelines it is even recommended as a first-line drug treatment for heavy menstruation without structural abnormality. The action of keeping the endometrium thin also leads to the effect of protecting the endometrium. However, since such therapeutic effect and suitability differ according to one's uterine condition and disease, it is good to first confirm through a visit whether it is a situation requiring treatment of women's disease. For those running menopausal hormone therapy alongside, endometrial protection is sometimes considered together in the context of hormone intensive care.

The much-asked insurance issue can be answered, in a word, as it depends on the purpose. Placement purely for the purpose of contraception is generally guided as non-covered, whereas when accompanied by an indication requiring treatment, such as heavy menstruation, severe menstrual pain, or adenomyosis, there is a possibility that coverage applies.

However, since even with the same symptom, whether it applies differs according to the examination findings and diagnosis, it is hard to declare by generalizing one person's situation. We guide on the exact insurance coverage through a consultation after a visit and necessary examinations. The cost too differs according to the device type and the content of care, so guiding after a consultation is accurate. As another test whose insurance criteria you may be curious about, you can also refer to the article on the health-insurance coverage criteria of the HPV test.

Before placement, the structural condition of the uterus and whether the procedure is possible must be confirmed first. Consultation on pregnancy and contraception overall is helped together at the pregnancy and contraception clinic. If you are curious about the choice that suits you and the possibility of insurance coverage, feel free to inquire.

Every day we ponder how to make our patients a little more comfortable and healthy. Today too we will take one more step forward. For questions, please inquire by chat consultation anytime.

Written by: Lee Dong-hee, Director · OB/GYN Specialist · View physician profile

First published January 6, 2024 · Last reviewed May 30, 2026

References: FSRH Guideline Intrauterine Contraception (2023), ACOG Practice Bulletin on Long-Acting Reversible Contraception (2017)

This article is intended to provide general health information and is not a substitute for individual diagnosis or treatment. If you have symptoms, please consult through a medical visit.