Structure
Levonorgestrel is a potent synthetic progestogen, the levorotatory isomer of norgestrel, enhancing its progestational activity.
Chemical Formula: C₂₀H₂₉NO₂
Mode of Action
Progestogen Activity: Binds to progesterone recep
tors, inhibiting ovulation and altering endometrial receptivity.
Cervical Mucus Thickening: Enhances cervical mucus viscosity, preventing sperm from reaching the ovum.
Endometrial Alteration: Thins the endometrial lining, reducing the likelihood of implantation.
Uses of Levonorgestrel
Oral Contraceptives: Widely used in combined oral contraceptive pills and progestin-only pills.
Emergency Contraception: Administered as a single-dose pill to prevent pregnancy after unprotected intercourse.
Menstrual Regulation: Helps in managing heavy menstrual bleeding and irregular cycles.