What are the side effects if you have mirena longer than 5 years?

Reversible birth control that works for a long time (up to 5 years).
The medication in the device is slowly released into the body over a 5-year period.

The levonorgestrel intrauterine device may become embedded into the wall of the uterus, or may perforate (form a hole) in the uterus. If this occurs, the device may no longer prevent pregnancy, or it may move outside the uterus and cause scarring, infection, or damage to other organs. If the device embeds in or perforates the uterine wall, your doctor may need to surgically remove the device.

Call your doctor at once if you have a serious side effect such as:

severe cramps or pelvic pain;
extreme dizziness, feeling like you might pass out;
heavy or ongoing vaginal bleeding, vaginal sores, vaginal discharge that is watery, foul-smelling discharge, or otherwise unusual;
severe pain in your side or lower stomach;
pale skin, weakness, easy bruising or bleeding;
fever, chills, or other signs of infection;
pain during sexual intercourse;
sudden numbness or weakness, especially on one side of the body;
sudden or severe headache, confusion, problems with vision, sensitivity to light;
jaundice (yellowing of the skin or eyes); or
signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may include:

irregular menstrual periods, changes in bleeding patterns or flow;
breakthrough bleeding, or heavier menstrual bleeding during the first few weeks after device insertion;
back pain;
headache, nervousness, mild dizziness;
nausea, vomiting, bloating;
breast tenderness or pain;
weight gain, acne, changes in hair growth;
mood changes, loss of interest in sex;
mild itching, skin rash; or
puffiness in your face, hands, ankles, or feet.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

Take care

Don't know about side effects, per se, but you can definitely get pregnant, as the levonorgesterel in the IUD will no longer be in effect. Increasing your risks of ectopic pregnancy.