All of the statements regarding progesterone only pill are true, except
High-Yield Explanation
Failure rate of combined OCP is 0.2/100 women years, whereas failure rate of progesterone only pill is about 0.5 - 2 per 100 women years of use. Progesterone only pill acts by thickening cervical mucous, causing atrophy of endometrium or by inhibiting ovulation.