Side Effects

Some users report the following:

  • Most commonly, changes in bleeding patterns,† including:
    • Lighter bleeding and fewer days of bleeding
    • Infrequent bleeding
    • Irregular bleeding
    • No monthly bleeding
    • Prolonged bleeding
  • Acne
  • Headaches
  • Breast tenderness or pain
  • Nausea
  • Weight gain
  • Dizziness
  • Mood changes

Other possible physical changes:

  • Ovarian cysts

Bleeding changes are normal and not harmful. If a woman finds them bothersome, counseling and support can help. 

Known Health Benefits

Known Health Risks

Help protect against:

  • Risks of pregnancy
  • Iron-deficiency anemia

May help protect against:

  • Endometrial cancer
  • Cervical cancer 


  • Menstrual cramps
  • Heavy monthly bleeding
  • Symptoms of endometriosis (pelvic pain, irregular bleeding)
  • Risk of ectopic pregnancy


  • In the short term PID may occur if the woman has gonorrhea or chlamydia at the time of insertion.







  • Puncturing (perforation) of the wall of the uterus by the LNG-IUD or an instrument used for insertion. Usually heals without treatment.

Very rare:

  • Miscarriage, preterm birth, or infection in the very rare case that the woman becomes pregnant with the LNG-IUD in place.


Correcting Misunderstandings


  • Can be used by women of any age, including adolescents.

  • Can be used by women who have had children and those who have not.

  • Do not increase the risk of contracting STIs, including HIV.

  • Do not increase the risk of miscarriage when a woman becomes pregnant after the IUD is removed.

  • Do not make women infertile.

  • Do not cause birth defects.

  • Do not cause cancer.

  • Do not move to the heart or brain.

  • Do not cause discomfort or pain for the woman or the man during sex. 

Why Some Women Say They Like the LNG-IUD
  • Prevents pregnancy very effectively
  • Makes bleeding lighter and can prevent monthly bleeding for many months (amenorrhea).
  • Is long-lasting
  • Is private—usually no one else can tell a woman is using contraception (sometimes a partner may feel the strings during sex)

  • Has no further costs for supplies after the IUD is inserted

  • Does not require the user to do anything once the IUD is inserted


† For definitions of bleeding patterns, see vaginal bleeding.