Mechanism of Action :
Pregnancy may be prevented through several mechanisms: Thickening of cervical mucus, which inhibits sperm passage through the uterus and sperm survival; inhibition of ovulation, from a negative feedback mechanism on the hypothalamus, leading to reduced secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH); altering the endometrium, which may affect implantation. Levonorgestrel is not effective once the implantation process has begun.
Indication :
Levonorgestrel is indicated for emergency contraception for the prevention of pregnancy following unprotected intercourse or possible contraceptive failure.