ATC code: G02BA03(Plastic IUDs with progestogen (levonorgestrel))
Mechanism of action
T-shaped device with levonorgestrel reservoir. Locally releases 12-20 µg/day – systemic exposure 100× lower than POPs. Acts via endometrial thinning, cervical mucus thickening, partial ovulation suppression (25-50% of women). Pearl Index 0.2. Three options: Mirena 52 mg (5 years), Kyleena 19.5 mg (5 years), Jaydess 13.5 mg (3 years).
Indications
A
Contraception
First line
Long-acting reversible contraception for 3-5 years. Per SEGO 2023, FSRH 2017, NG88 2018, first-line, including nulliparous women. Mirena is also approved for heavy menstrual bleeding (90% reduction by month 6). Office insertion, 5-10 minutes with mild discomfort.
Contraception during breastfeeding. MEC 2015 category 2 in first 4 weeks postpartum (theoretical perforation risk, acceptable in practice), category 1 from week 4. Local levonorgestrel exposure minimally affects lactation. RID about 1.3% (via maternal systemic circulation). Does not reduce milk supply.
Heavy menstrual bleeding (Mirena 52 mg). Per NG88 2018 and SEGO 2023, first-line. 70-90% blood loss reduction by month 6. Effective alternative to hysterectomy and endometrial ablation in women with preserved reproductive function.
Insertion by a gynecologist on any day of the cycle with a negative pregnancy test. Postpartum, ideally at 4-6 weeks. After abortion – immediate. Fertility returns immediately after removal.
Monitoring
String check at 4-6 weeks after insertion and at each gynecologic visit. Ultrasound if displacement or expulsion suspected. Expected changes: amenorrhea in 20-50% by year 1 (Mirena), irregular spotting in first 3-6 months. Not pathological.
Check interaction with another drug
Opens the checker prefilled with this drug. Pick the second one from your regimen.
Severe liver disease, breast cancer (for the hormonal aspect)
Serious adverse effects
Uterine perforation (0.1%)
Expulsion (2-10%)
Ectopic pregnancy if method fails (0.02%)
Pelvic infection in first 3 weeks
Common adverse effects
Pelvic pain on insertion
Irregular bleeding in first 3-6 months
Amenorrhea (20-50% by year 1)
Acne
Breast tenderness
Functional ovarian cysts
PregnancyFDA X
Remove as soon as possible if pregnancy occurs due to infection and miscarriage risk.
Breastfeeding
Hale L2 · Probably compatible
WHO MEC 2015 category 2 in first 4 weeks postpartum, then 1. Local levonorgestrel release is minimally systemic. RID about 1.3% (for the systemic portion), Hale L2. Does not reduce milk supply.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
Frequently asked
What is Levonorgestrel (intrauterine system) used for?
Levonorgestrel (intrauterine system) is evaluated for the following indications with varying evidence strength: Contraception (evidence tier A), Heavy menstrual bleeding (evidence tier A), Contraception during breastfeeding (evidence tier A). See the full indication matrix with dosing and citations above on this page.
What are the side effects of Levonorgestrel (intrauterine system)?
Common side effects of Levonorgestrel (intrauterine system) (≥ 1 in 100): Pelvic pain on insertion, Irregular bleeding in first 3-6 months, Amenorrhea (20-50% by year 1), Acne, Breast tenderness, Functional ovarian cysts. See the Safety section for uncommon and serious reactions.
Is Levonorgestrel (intrauterine system) safe during pregnancy?
FDA category X. Remove as soon as possible if pregnancy occurs due to infection and miscarriage risk.
Is Levonorgestrel (intrauterine system) compatible with breastfeeding?
WHO MEC 2015 category 2 in first 4 weeks postpartum, then 1. Local levonorgestrel release is minimally systemic. RID about 1.3% (for the systemic portion), Hale L2. Does not reduce milk supply.
Who should not take Levonorgestrel (intrauterine system)?
Levonorgestrel (intrauterine system) is contraindicated in: Confirmed or suspected pregnancy; Active pelvic inflammatory disease (PID); Uterine cavity anomalies (fibroid >4 cm, septum); Cervical or endometrial cancer; Unexplained uterine bleeding. Full list in the Safety section.