The progesterone component of oral contraceptive pills acts by :
Action of OCPs: 1.The combined oral pill suppresses pituitary hormones,FSH and LH peak and through their suppression prevents ovulation. 2.Progestogen causes atrophic changes in the endometrium and prevents nidation. Progestogen also acts on the cervical mucus making it thick and tenacious and impenetrable by sperms. 3.It also increases the tubal motility, so the feilized egg reaches the uterine cavity before the endometrium is receptive for implantation. Ref: Shaw Gynecology 17 e pg 264.
Preventing ovulation
Inhibiting implantation
Bringing about alterations in cervical mucus
All of the above
Contraception