Levonorgestrel

What it is and how it works

Mechanism of Action The local mechanism by which continuously released LNG contributes to the contraceptive effectiveness of Kyleena has not been conclusively demonstrated. Studies of Kyleena and similar LNG IUS prototypes have suggested several mechanisms that prevent pregnancy: thickening of cervical mucus preventing passage of sperm into the uterus, inhibition of sperm capacitation or survival, and alteration of the endometrium .

Indications

Kyleena is indicated to prevent pregnancy for up to 5 years. Replace the system after 5 years if continued use is desired. Kyleena is a progestin-containing intrauterine system (IUS) indicated for prevention of pregnancy for up to 5 years.

Dosage and administration (summary)

• Release rate of levonorgestrel (LNG) is 17.5 mcg/day after 24 days and declines to 7.4 mcg/day after 5 years; Kyleena must be removed or replaced after 5 years. • To be inserted by a trained healthcare provider using strict aseptic technique. Follow insertion instructions exactly as described. • Patient should be re-examined and evaluated 4 to 6 weeks after insertion; then yearly or more often if clinically indicated. Dosing Over Time Kyleena contains 19.5 mg of levonorgestrel (LNG) released in vivo at a rate of approximately 17.5 mcg/day after 24 days. This rate decreases progressively to 9.8 mcg/day after 1 year and to 7.4 mcg/day after 5 years.

Contraindications

The use of Kyleena is contraindicated when one or more of the following conditions exist: • Pregnancy or suspicion of pregnancy • For use as post-coital contraception (emergency contraception) • Congenital or acquired uterine anomaly, including fibroids, that distorts the uterine cavity • Acute pelvic inflammatory disease (PID) or a history of PID unless there has been a subsequent intrauterine pregnancy • Postpartum endometritis or infected abortion in the past 3 months • Known or suspected ute…

Warnings and precautions

• Remove Kyleena if pregnancy occurs with Kyleena in place. If pregnancy occurs, there is increased risk of ectopic pregnancy including loss of fertility, pregnancy loss, septic abortion (including septicemia, shock and death), and premature labor and delivery. ( 5.1 , 5.2 ) • Group A streptococcal infection has been reported following insertion of LNG IUS; strict aseptic technique is essential during insertion. • Before using Kyleena, consider the risks of PID. • Uterine perforation may occur and may reduce contraceptive effectiveness or require surgery.

Pregnancy

Pregnancy Risk Summary The use of Kyleena is contraindicated in pregnancy or with a suspected pregnancy and Kyleena may cause adverse pregnancy outcomes . If a woman becomes pregnant with Kyleena in place, the likelihood of ectopic pregnancy is increased and there is an increased risk of miscarriage, sepsis, premature labor, and premature delivery …

Storage and supply

Kyleena (levonorgestrel-releasing intrauterine system), containing a total of 19.5 mg LNG, is available in a carton of one sterile unit. NDC# 50419-424-01 Kyleena is supplied sterile. Kyleena is sterilized with ethylene oxide. Do not resterilize. For single use only. Do not use if the inner package is damaged or open.

Source: Levonorgestrel (Kyleena) — US FDA prescribing information, 2025-10-23, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.