Mirena is a hormonal form of birth control that can cause side effects. Some of the common side effects of Mirena include:

• Unscheduled (spotty) bleeding
• Missed periods
• Abdominal or pelvic pain
• Breast pain or tenderness
• Acne
• Headaches or migraines
• Mood changes
• Irregular bleeding, which can improve after six months of use
• Cramping or pelvic pain

Less common side effects include benign ovarian cysts, heavier periods, inflammation or infection of the vulva and vagina (vulvovaginitis), and in rare cases, severe pelvic pain or infections. Some women may also experience long-term changes such as lighter periods or no periods at all.

Serious side effects of Mirena include uterine wall perforation while planting or removing the device, severe infection or sepsis, risk of ectopic pregnancy, and pelvic inflammatory disease (PID) . PID is a bacterial infection that affects the reproductive organs, such as the uterus, and can lead to infertility if not treated promptly. Other serious side effects include vomiting or nausea, hair loss, painful intercourse, fatigue, unexplained weight gain, decreased sex drive, and depression, anxiety, mood swings, irritability, or lack of interest in normal activities.

It is important to talk to a doctor about the potential risks and benefits of Mirena before choosing it as a form of birth control. If you experience any severe or persistent side effects, contact your doctor immediately.