Mirena, a levonorgestrel-releasing intrauterine system (IUS), is a highly effective long-acting reversible contraceptive (LARC) and a common treatment for heavy menstrual bleeding. This small, T-shaped device is inserted into the uterus, continuously releasing a low dose of progestin. Knowing what to expect after Mirena insertion can help individuals feel more prepared.
What to Expect Immediately After
Immediately after Mirena insertion, cramping, similar to menstrual cramps, is common for the first few hours to days. This is a normal uterine adjustment. Light bleeding or spotting, often brown or dark, is also observed.
Mild dizziness or nausea may also occur directly after insertion. These effects are temporary. Over-the-counter pain relievers, like ibuprofen, can help manage discomfort. If intense pain or bleeding persists over 30 minutes, or dizziness does not resolve, contact a healthcare provider; this could indicate improper placement.
Changes in the First Few Months
The body adjusts during the first few months after Mirena insertion, leading to changes in menstrual patterns. Irregular bleeding, including spotting, prolonged bleeding, or unpredictable bleeding, is common during the initial three to six months. This adaptation is due to the levonorgestrel hormone released by the IUD.
Over time, many users experience a significant reduction in menstrual flow, with periods becoming lighter, shorter, or even stopping entirely (amenorrhea). This occurs because progestin thins the uterine lining. Some individuals may also notice hormonal side effects like breast tenderness, headaches, or mood fluctuations. These effects usually lessen as the body adapts to localized hormone levels.
Signs Requiring Medical Attention
While many post-insertion symptoms are normal, certain signs require immediate medical attention. Severe or worsening pain not relieved by over-the-counter medication needs evaluation by a healthcare provider. Unusually heavy bleeding, defined as soaking through one or more pads or tampons every hour for several consecutive hours, also warrants prompt medical contact.
Symptoms like fever, chills, or unusual, foul-smelling vaginal discharge can signal a potential infection, including pelvic inflammatory disease (PID), requiring urgent treatment. If pregnancy is suspected, or if symptoms like unexplained abdominal pain or abnormal vaginal bleeding occur, contact a healthcare provider immediately due to a rare but increased risk of ectopic pregnancy with an IUD. Changes in IUD strings (feeling significantly longer, shorter, or being unable to feel them) suggest the device may have moved or been expelled, necessitating a check by a medical professional.
Follow-Up and Long-Term Expectations
A follow-up appointment is typically scheduled a few weeks after Mirena insertion, usually four to six weeks, to ensure correct IUD positioning. This visit allows the healthcare provider to check the strings and confirm placement.
Mirena begins working immediately if inserted within the first seven days of a menstrual period. If inserted at any other time, use a backup birth control method, like condoms, for at least seven days to prevent pregnancy. Mirena is approved to prevent pregnancy for up to eight years. For heavy menstrual bleeding treatment, Mirena is approved for up to five years, though it can often continue to manage bleeding longer if desired and symptoms remain controlled.