Mirena (Levonorgestrel intrauterine system) — Uses, Dosage, Side Effects & Safety

Drug class: Progestin-only intrauterine contraceptive

Overview

Mirena is a long-acting reversible contraceptive device placed inside the uterus to prevent pregnancy for up to 8 years. It contains levonorgestrel, a type of progestin hormone, which is slowly released into the uterus. Mirena works mainly by thickening cervical mucus to block sperm, thinning the uterine lining to prevent implantation, and sometimes suppressing ovulation. Mirena is also approved for treating heavy menstrual bleeding in women who choose intrauterine contraception. Most women experience lighter periods, and some may stop having periods altogether while using Mirena. It is a highly effective, low-maintenance birth control option, but it must be inserted and removed by a healthcare professional.

Therapeutic uses

  • Long-term contraception
  • Treatment of heavy menstrual bleeding (menorrhagia)
  • Protection against endometrial hyperplasia during estrogen replacement therapy

Common side effects

  • Abdominal pain
  • Ovarian cysts
  • Headache
  • Acne
  • Breast tenderness
  • Changes in bleeding patterns
  • Pelvic inflammatory disease
  • Uterine perforation

Frequently Asked Questions about Mirena

How effective is Mirena at preventing pregnancy?

Mirena is over 99% effective at preventing pregnancy, making it one of the most reliable forms of reversible contraception available.

How soon after insertion does Mirena start working?

If inserted during the first 7 days of your menstrual cycle, Mirena is effective immediately. If inserted at another time, use backup contraception for 7 days.

Can Mirena be used to treat heavy periods?

Yes, Mirena is approved for the treatment of heavy menstrual bleeding in women who choose intrauterine contraception.

What should I do if I cannot feel the Mirena strings?

If you cannot feel the strings or suspect the device has moved or been expelled, use backup contraception and contact your healthcare provider as soon as possible.

Can I get pregnant after Mirena is removed?

Yes, fertility typically returns quickly after Mirena is removed, and most women can become pregnant within a few months.

Does Mirena protect against sexually transmitted infections (STIs)?

No, Mirena does not protect against HIV or other STIs. Use condoms to reduce your risk of infection.

How long can Mirena stay in place?

Mirena can be used for up to 8 years for contraception. For heavy menstrual bleeding, it is approved for up to 5 years.

Educational information only. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.