Levosert Shi (Levonorgestrel)

Levosert Shi is a levonorgestrel‑based intrauterine system that acts on the hormonal regulation of the menstrual cycle and uterine environment.

• Contraception: offers highly effective, reversible birth control for up to several years.
• Heavy menstrual bleeding: reduces menstrual blood loss and improves anemia associated with menorrhagia.
• Menstrual regulation: helps normalize irregular uterine bleeding patterns in women seeking hormonal management.

• Levonorgestrel released from the intrauterine system diffuses locally into the endometrium and cervical mucus. It suppresses ovulation, thickens cervical mucus to impede sperm passage, and induces endometrial atrophy, creating an environment that prevents implantation and reduces menstrual blood loss.

Levosert Shi may be associated with a range of adverse reactions.

Common Side Effects

• Irregular bleeding or spotting, especially during the first months.
• Amenorrhea (absence of periods) after prolonged use.
• Pelvic or uterine cramping.
• Breast tenderness or enlargement.
• Ovarian cyst formation, usually asymptomatic.
• Headache or mild nausea.

Serious or Rare Side Effects

• Uterine perforation during insertion.
• Device expulsion or displacement.
• Pelvic inflammatory disease or severe infection.
• Ectopic pregnancy if contraception fails.
• Severe allergic reaction to device components.
• Thromboembolic events, though rare with progestin‑only systems.

Before insertion, clinicians should evaluate patient suitability and counsel on potential risks.

• Pregnancy screening: confirm the patient is not pregnant before insertion.
• Uterine assessment: exclude fibroids, congenital anomalies, or active infection.
• Infection risk: avoid insertion during untreated pelvic infection.
• Bleeding counseling: inform about possible changes in menstrual pattern.
• Follow‑up: schedule post‑insertion checks to verify placement.
• Store at room temperature: keep in original packaging, protect from moisture and direct sunlight.

Levonorgestrel IUS may have pharmacokinetic interactions that affect contraceptive efficacy.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin) that may lower levonorgestrel levels.
• Concurrent use of uterine‑acting devices that could displace the system.

Moderate Interactions (Monitor Closely)

• Moderate CYP3A4 inducers (e.g., efavirenz, St. John's wort) requiring efficacy monitoring.
• Antifungal agents such as ketoconazole that may increase levonorgestrel exposure.
• Certain antiretrovirals (e.g., protease inhibitors) that could alter hormone metabolism.