Each pill contains hormones, which prevent pregnancy by suppressing the release of the ovum (egg cell) from the ovaries.
What are the health benefits of oral contraceptive pills: Beside the prevention of pregnancy, regular use of oral contraceptives may provide some other benefits: Menstrual cycle may become more regular.
Menstrual pain may become less frequent and lighter.
Cysts in ovaries and benign cysts or lumps in breasts may occur less frequently.
Acute pelvic inflammatory diseases may occur less frequently.
It may provide protection against some forms of cancers of the ovaries and uterus.
How effective are oral contraceptive pills: Oral contraceptives or "birth control pills" are intended to prevent pregnancy. If they are taken correctly on schedule, the chance of becoming pregnant is very low.