How do oral pills help in birth control? Name two common pills used.

Explanation

Oral contracptive pills contain either progesterone alone or a combinations of progresterone and estrogen.
They help in birth control by:
(a) Inhibition of ovulation.
(b) Alternation of endometrium of uterus to make it unsuitable for implantation.
Two common types of pills used are
(a) Minipills-e.g., Saheli
(b) Combined pills e.g., Mala D, Mala N.