Comparing the Nexplanon Implant and the Mirena IUD

When it comes to birth control, you can choose from many options that provide the same benefit. Implantable contraceptive devices are long-acting reversible contraceptives that do not require the user to put forth significant effort or need to recall medication regimens. Most of these devices approved by the Food and Drug Administration (FDA) are progesterone only. These may provide the benefits of improving heavy menstrual flow, alleviate painful periods, and help with symptoms of endometriosis. Additionally, these devices can be a great contraceptive method for women who cannot use combination oral contraceptives due to the estrogen in that type of birth control.

Your gynecologist will evaluate you and explain the various options for birth control. If you select one of the long-acting reversible contraceptive methods below, you will get an overview of the procedure, followed by an insertion. Although there are various implantable contraceptive devices, this article will explore the Nexplanon and Mirena contraceptive devices.

How Nexplanon Works

Nexplanon^® (etonogestrel implant) is the brand name for a progesterone-only implant rod that is inserted under the skin in the arm. The procedure can be performed as an outpatient at your doctor’s office. With Nexplanon, there is a 0.05% chance of pregnancy during its first use, with fewer than 1 in 1,000 women becoming pregnant over a 3-year use. The FDA has approved Nexplanon for contraceptive use for 3 years and may still be efficacious 1–2 years after the FDA-approved duration. This implant primarily works by suppressing ovulation and secondarily by thickening cervical mucus to prevent sperm motility. It also thins the lining in the uterus to prevent the implantation of a fertilized egg if ovulation does happen.

Nexplanon Side Effects

When the implant is inserted, you may notice changes in the patterns of your menstrual flow, some irregular and infrequent spotting, and even the absence of periods. Other reported side effects of Nexplanon use include headache, breast tenderness, irritation of the vagina, and gastrointestinal discomfort. Another side effect of implantable contraceptive devices like Nexplanon is weight gain: 12% of implant uses report weight gain, with only 2–7% discontinuing their use due to the weight gain. Complications associated with insertion are minimal but can include some pain, mild bleeding, and bruising.

How Mirena Works

Mirena^® (levonorgestrel-releasing intrauterine system) is another long-acting reversible contraceptive device approved by the FDA for up to 6 years of continuous use as a contraceptive method and up to 5 years to treat heavy menstrual flow. It is a T-shaped device that your doctor will insert into your uterus after performing a thorough examination. The Mirena IUD works by thinning the uterus lining and triggering the body’s normal reaction to a foreign body, making it inhospitable for sperm to survive. It changes the thickness of cervical mucus to prevent sperm motility. Mirena also alters the transport of an egg when ovulation occurs; and, in some women, suppresses ovulation.

Advantages of Mirena

One of the advantages of choosing the Mirena IUD is that no dosing regimen requirements need to be remembered after it has been inserted. The Mirena IUD contains only progesterone, so it is great for women with a history of blood clots, obesity, seizure disorders, ectopic pregnancy, and contraindications to medications that contain estrogen. Above all, it is a cost-effective method due to its potential for long-term use. The rates of unintended pregnancy with the use of IUD range from 0.2–0.3% at 1 year.

Mirena Side Effects

Some side effects of the Mirena IUD include headaches, breast tenderness, mood changes, ovarian cyst formation, and some breakthrough bleeding. In rare cases, women have developed acne with the use of the Mirena IUD.

According to the American College of Obstetricians and Gynecologists, long-active reversible contraceptives like Nexplanon the Mirena IUD have few contraindications and can be offered as safe and effective contraceptive options for most women. Speak with your gynecologist about which long-acting reversible contraceptive is best for you. For any method of birth control, it is up to you, the patient, to decide what works best for you depending on your schedule, routine, or any other benefits you want when starting a medication regimen.

Your local pharmacy can help guide you on your savings for your prescription medication. The Nexplanon implant and Mirena IUD are only available at your doctor's office. But for other birth control methods that you can fill at your local pharmacy, the ScriptSave^® WellRx card may help you save on the price you pay for your prescriptions.

Gabriel Espinoza, MD has experience in caring for patients in both primary care and emergency settings. Some of the topics he has focused on during his medical career include various areas in public health, pediatrics, and wellness. He has coauthored a chapter on the utility of point of care ultrasound in the diagnoses of various eye conditions. The content written by Dr. Espinoza is for information and educational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician with any questions you may have regarding a medical condition.

References:

https://www.ncbi.nlm.nih.gov/books/NBK536949/

https://journals.lww.com/greenjournal/Fulltext/2017/11000/PracticeBulletinNo186LongActingReversible.50.aspx

https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/021529s018lbl.pdf

https://www.merckmanuals.com/professional/gynecology-and-obstetrics/family-planning/intrauterine-device-iuds-iud