What is premature ovarian failure? The ovary is an important organ of the female reproductive system, its main function is to produce eggs and female hormones. As women age, ovarian function naturally declines, but in some cases, premature ovarian failure occurs. Premature ovarian failure, also known as early ovarian failure, is a condition in which young women enter menopause earlier than expected. Typically, a woman\’s ovaries stop working properly between the ages of 45 and 55, but women with premature ovarian failure will start to work again between the ages of 40 and 55.