Drug makers are finding a new way to market birth-control pills: as a way to help women curb or eliminate periods.

The concept of "period management" -- using hormones to alter or eliminate the menstrual cycle -- has been around for years. Doctors have often adjusted birth-control pill doses to ease painful or excessive periods in women with endometriosis or other health problems affected by the menstrual cycle. Brides-to-be have long used continuous doses of birth-control pills as a way to ensure they don't have their periods on their wedding day or honeymoon week.

Now pharmaceutical companies are getting in on the act. Barr Laboratories just won approval from the Food and Drug Administration for Seasonique, a three-month regimen that includes 91 pills in a pack and reduces periods to just four a year. The firm already markets Seasonale, another three-month pill. Warner Chilcott's Loestrin 24 Fe and Berlex's Yaz offer 24-day dosing that results in shorter monthly periods. Early next year, an FDA advisory committee is expected to review Lybrel, a 365-day regimen from Wyeth that eliminates a woman's period altogether.

"It's not a new idea -- it's just become newly popular," says Leslie Miller, associate professor of obstetrics and gynecology at the University of Washington in Seattle, who helps patients with period management. "Female doctors have always known you can skip your period on the pill."

Some women might be uncomfortable with the idea of altering or eliminating the monthly period. Women grow up knowing that an irregular period or no period can be a sign of an underlying health problem.

The New Pill

Some oral contraceptives to help women manage their periods:

  • Loestrin 24 Fe: 24-day pill pack with four iron tablets; typically results in periods of 3 days or less.
  • Yaz: Contains 24 hormone pills and four placebos; offers shorter monthly periods. FDA approved to reduce premenstrual symptoms.
  • Seasonale/Seasonique: Package of 91 pills; 4 periods a year.
  • Lybrel: A 365-day pill that eliminates periods in most women; awaiting FDA approval.

But the reality is, a lifetime of monthly periods isn't quite what nature intended. Women today menstruate nearly three times as often as their ancestors, who typically had more children and spent years breast-feeding, a practice that can naturally suppress menstruation. But with the onset of modern birth-control methods, and the fact that girls tend to menstruate earlier than in generations past, women now have more periods. Today, the average North American woman has about 400 periods in her lifetime. By comparison, an aboriginal woman in Northern Australia has about 150 periods during her life.

Some doctors believe reducing the number of monthly cycles in a woman's lifetime actually is better for her health. Keeping a woman's hormone levels constant and suppressing menstruation can lower risk for endometriosis, mood disorders, headache and ovarian cancer. (It's already known that monthly use of birth-control pills, which eliminates the ovulation process, lower a woman's risk for ovarian cancer.)

In a woman who doesn't use oral contraception, the lining of the uterus thickens to prepare for a fertilized egg. If no conception occurs, the uterine lining sheds, resulting in menstruation. Birth-control pills prevent ovulation by suppressing a woman's natural hormones, so no egg is released. The pill also results in changes that hinder the movement of sperm and prevent the uterine lining from developing normally.

What many pill users don't understand is that the period they experience each month is artificially induced by the hormones in birth-control pills. There's no medical need to induce a period -- the pill was simply designed this way in the 1950s as a way to boost women's acceptance of oral contraception.

But recent surveys show that women today like the idea of reducing or eliminating their periods. Dr. Miller notes that women can manage their periods with regular birth-control pills, though it's not always convenient. Pills typically come in packs with 21 active pills and 7 placebos. To take a pill every day, the woman would need 18 packs a year. Many insurance companies won't pay for more than 13 packs a year unless the extra pills are needed for a specific medical condition. However, the new period-management pill packs being sold by drug companies typically are covered by insurance.

Health Mailbox

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All birth-control pills carry some risks, including a slight risk for blood clots. So far, there's no evidence that women who take long-cycle birth-control pills for three months or even a year have a higher rate of side effects than women who take the pills in monthly doses. In fact, women who take continuous birth-control pills usually end up ingesting fewer hormones over the course of a year because they use a lower-dose pill every day rather than a higher dose pill for 21 days.

One downside of period management is that it can result in some spotting or breakthrough bleeding, but it often disappears over time. In studies of the new 365-day-a-year pill Lybrel, about 80% of women no longer needed to use sanitary protection after a year on the pill, says Majorie Miller, Wyeth's assistant vice president and global business manager for contraception.

Pills aren't the only option. Depo-Provera shots and Mirena, a hormone-releasing intrauterine device, can stop periods, but some women may continue to have irregular bleeding. Ablation surgery to destroy the lining of the uterus can reduce or eliminate periods, but often destroys fertility as well.

Email questions to healthjournal@wsj.com; read my responses in Health Mailbox inside this section.