• It is the most effective reversible method ever developed!
  • It prevents ectopic pregnancies (15 times lower than non-contraceptors).
  •  It decreases menstrual cramping and dramatically decreases menstrual blood loss (a 97% reduction in menstrual blood loss in one study). but probably about a 90% reduction in blood loss on average). Some women experience an absence of menstrual bleeding after one year (about 20%). This IUD may be left in place for at least 5 years (probably effective for 7 or even more years).
  • Mirena decreases menstrual cramps and pain. Mirena improves endometriosis
  • Mirena prevents endometrial hyperplasia and reduces a woman’s risk for endometrial cancer.
  • Mirena is safe, inexpensive over time, and provides extremely effective long-term contraception from a single decision.
  • One of the costs of any contraceptive is the cost to you should your contraceptive fail. Given the extremely low failure rate of Mirena, a person using this method is far less likely to have the emotional and financial expenses associated with an unintended pregnancy. IUDs are the most cost effective contraceptives over time.
  • Mirena my possible reduce a woman’s risk for developing pelvic inflammatory disease by producing a very thick cervical mucus preventing the ascent of microorganisms that cause PID
  • All you have to do is check for the strings each month (many clinicians no longer recommend this after several months).
  • May be used by postmenopausal women on estrogen therapy to protect the endometrium against endometrial cancer.
  • Once Mirena is removed, fertility returns immediately. Approximately 8 out of every 10 women who want to become pregnant will become pregnant in the first year after Mirena is removed.


  • Do NOT start this method of birth control unless you will find it acceptable to have your periods change.  They WILL change a lot.
  •  There may be more bleeding days than normal for the first few months and less than normal after 6 to 8 months. If your bleeding pattern is bothersome, contact your clinician. There are medications which can help you have a better pattern of bleeding.
  • The IUD does not provide protection against sexually transmitted infections. Use condoms if there is any risk.
  • There may be a high initial cost of insertion.
  • There is a very slightly increased risk of pelvic infection in the first 20 days after Mirena insertion.
  • The risk of uterine perforation at the time of Mirena insertion is also low – between 1 in 1,000 and 1 in 2,000.
  • Mirena gives off very low amounts of a progestin into the blood stream and can lead to some systemic effects such as weight gain and acne, but these are uncommon


Mirena can be inserted by your clinician or at a Planned Parenthood or health department clinic. Most clinics insert IUDs when a woman has her period or within 7 days of the start of the period. If the risk of pregnancy can be excluded IUD may be inserted at other times in the cycle. 

                                          Revisions as of 3/24/10