Mirena is FDA-approved for up to 8 years of pregnancy prevention. After the eighth year, it needs to be removed and replaced if you want to continue using it. This timeline was extended from the original 5-year approval, so if you were told years ago that Mirena lasts 5 years, the updated guidance gives you significantly more time.
How the 8-Year Timeline Works
Mirena contains 52 mg of a synthetic hormone called levonorgestrel, which it releases slowly into your uterus over the course of its lifespan. In the first few weeks, the device releases about 21 micrograms per day. That rate drops steadily over time: by year 5, it’s down to roughly 11 micrograms per day, and by year 8, it’s releasing about 7 micrograms per day.
Even at that lower dose, the device still works. A study published in The Journal of the American Board of Family Medicine found that the cumulative failure rate during years 6 through 8 was just 0.68%. The three-year Pearl Index for that extended window was 0.28, which means fewer than 1 in 300 women using Mirena during those later years became pregnant. That’s still exceptionally effective, comparable to many contraceptive methods at their peak performance.
What Changes as Mirena Ages
The declining hormone output doesn’t just affect contraception. It also influences how Mirena manages your periods. Many people experience very light periods or no periods at all during the first few years. As the hormone release tapers, some users notice their periods gradually return or become slightly heavier in years 6 through 8. This is normal and doesn’t mean the device has stopped working for pregnancy prevention.
Mirena is also used to treat heavy menstrual bleeding. The FDA-approved labeling covers both indications under the same 8-year timeframe. If you had Mirena placed specifically for heavy periods, you may find that the bleeding management becomes less dramatic in the later years as hormone levels decrease. That said, the device typically continues to reduce flow compared to what you experienced before insertion.
What Happens at the 8-Year Mark
When your 8 years are up, removal and replacement can happen in a single office visit. If you want to continue using Mirena, your provider can place a new one immediately after removing the old one, during any point in your cycle. There’s no required waiting period between the two.
The removal itself is usually faster than the original insertion. Your provider pulls gently on the strings, and the device’s arms fold up as it slides through the cervical canal. Most people describe it as a brief cramp. If you’re getting a new one placed at the same time, expect the insertion cramps you remember from the first time around.
Fertility After Removal
Mirena doesn’t cause any delay in fertility once it’s removed. Unlike some hormonal methods that can take months to fully clear your system, Mirena’s effects are localized to the uterus, so your body returns to its natural cycle quickly. Most people ovulate within a few weeks of removal.
For women under 35, the typical chance of conceiving is about 20% per menstrual cycle. About 60% conceive within 6 months of removal, and 85% to 90% conceive within a year. A large review of nearly 2,400 IUD users found that 83% achieved pregnancy within 12 months of having their device removed. These rates are essentially the same as for women who were never on any contraception at all.
Can You Keep It Longer Than 8 Years?
Some research suggests Mirena may remain effective beyond its approved window, but the FDA labeling is clear: replace it after year 8. The 8-year mark is where the manufacturer’s clinical data ends, so effectiveness beyond that point isn’t guaranteed or officially supported. Using it past 8 years means you’re in uncharted territory in terms of verified protection, and the already-declining hormone levels continue to drop. If avoiding pregnancy is important to you, sticking to the approved timeline is the safest approach.
If your Mirena is approaching its expiration and you’re not sure when it was placed, your provider’s office will have the insertion date on file. Some people also find it helpful to set a calendar reminder for their replacement date, since 8 years is a long time to remember a specific appointment.