How does Mirena stop periods?

Mirena is a hormonal intrauterine device placed inside the womb. It releases levonorgestrel mainly at the uterine lining, where it makes the lining thinner and cervical mucus thicker. With less lining to shed, monthly bleeding often becomes lighter. Some people eventually have no bleeding, while others continue to have occasional spotting or light periods.

Irregular bleeding is common during the early adjustment period. Mirena can reduce heavy bleeding linked with conditions such as fibroids or adenomyosis, but it does not remove those conditions. A [Hormonal IUD Device](/materials/hormonal-iud-device/) may also provide contraception; your clinician can explain its duration and suitability.

Before insertion, discuss your bleeding pattern, pregnancy plans, pelvic symptoms and any history of womb or cervical disease. After placement, learn how to check the threads if your clinician recommends it and attend follow-up if arranged. Keep a record of bleeding, pain and new symptoms so changes are easier to describe.

Heavy bleeding can contribute to [Iron Deficiency Anaemia](/conditions/iron-deficiency-anaemia/). Other causes of troublesome periods include [Uterine Fibroids](/conditions/uterine-fibroids/), [Adenomyosis](/conditions/adenomyosis/) and [Endometrial Hyperplasia](/conditions/endometrial-hyperplasia/).

Seek prompt medical advice for severe or persistent pelvic pain, fever, unusual discharge, very heavy bleeding, a positive pregnancy test, or if you cannot feel the threads when you normally can. Urgent assessment is needed for sudden severe pain, faintness or heavy bleeding. A clinician can check for infection, displacement, pregnancy or another cause of symptoms.

Ask whether Mirena fits your medical history, when bleeding changes are expected, how its position will be checked, and what alternatives exist if spotting continues. Ask how to distinguish expected cramps from symptoms that need review.