The hormones that suppress ovulation can cause the hair to thin in some women, particularly those with a family history of hair loss.

It has several contraceptive qualities but works chiefly by suppressing ovulation.

Experts note that progestogens have been successful in suppressing ovulation in more than 40 mostly captive species.

Breastfeeding greatly suppresses ovulation, but eventually an ovum is released.

Dr. Hanson said that for most women, they work like oral contraceptives, suppressing ovulation.

Breastfeeding may delay the return to fertility for some women by suppressing ovulation.

Oral contraceptives consist of the two female hormones, estrogen and progestin, which, taken continuously, suppress ovulation.

On the other hand, bearing several children, especially starting before age 30, breast-feeding and taking birth control pills, both of which suppress ovulation, are protective.

Medication that suppresses ovulation has been shown to lower the risk of ovarian cancer.

Women who took birth control pills, with similar hormones, are less likely than nonusers to develop ovarian cancer, probably because the hormones suppress ovulation.