The No-Period Pills

The newest birth control pills suppress women's menstrual cycles. But is this wise?

Medically Reviewed by Michael W. Smith, MD on September 08, 2003
5 min read

Let's face it, many women dread getting their monthly period. So take a minute to imagine this: What if you could take a birth control pill that reduced your periods from 13 to 4 each year? What if you could schedule life's big events - vacation, a wedding, family gatherings - around your "spring" period, or your "summer" period, or your "fall" period?

Pharmaceutical companies and many doctors are betting that women will jump at the chance. The first of these so-called continuous birth control pills, Seasonale from Barr Laboratories, will hit the market this fall. Others will likely soon follow. Surveys have shown that many women are enthusiastic about the idea of having fewer periods. Already, researchers at a number of institutions are now studying a pill that would involve menstruating only once a year. But a few gynecologists worry these pills may boost a woman's lifetime hormone exposure, with unforeseen health consequences.

The truth is, some women have been using birth control pills to suppress their periods for decades. All you have to do is buy three extra packets pills a year, and substitute your extra active pills for the placebos each month. But many women don't know about this option. It's certainly not advertised. And insurers usually won't pay for the extra pills. As a result, continuous birth control pills could create huge new demand.

Is it safe to turn off your cycle for so long? Many doctors say yes. In fact, oral contraceptives were originally designed as a continuous-hormone model, but the "placebo week" was inserted for "purely cultural reasons," says Carolyn Westhoff, MD, professor of obstetrics and gynecology at Columbia University. "It was thought that women would find it reassuring to get a period every month. The week off was inserted not for biological reasons, but just to make women and doctors more comfortable." In fact, she says, the overall hormonal dosage found in the new Seasonale pill is lower than that in the most popular oral contraceptive on the market today, Ortho Tri-Cyclen.

Mitchell Creinin, MD, is a researcher studying the one-year pill, and he agrees. "The idea that a woman 'needs' to have a period is folklore. The blood doesn't build up inside, and it has nothing to do with cleaning out your system or proving that you're normal," says Creinin, director of family planning in the obstetrics and gynecology department of the University of Pittsburgh's Magee-Women's Hospital. "There's no biological plausibility that a one-week break confers any protection against anything. At the turn of the century, the average number of menses per year was one or two, because women were breastfeeding or pregnant more often."

So far, these researchers say, the most common drawback to continuous birth control is that some women have unpredictable spates of breakthrough bleeding. "Women will have individual responses to this regimen," says Westhoff. "Some women will respond very well, won't have any breakthrough bleeding at all. Others will have more spotting, and some of those women will probably want to go back to the original method and know when they're going to bleed. That's why we want to have a lot of options available. No birth control method is going to be ideal for everybody."

Other doctors, however, urge caution. They say continuous birth control may increase the amount of estrogen and progesterone that some women take in their lifetimes. The health effects of this experiment in convenience may not be known for years. After all, millions of menopausal women took hormone replacement therapy (HRT) for decades before the risks became evident.

"If you look at the normal physiology of the menstrual cycle, things like the breasts and the liver need a break from continuous high estrogen, and there's a break during that time around the menstrual flow," says Jerilynn Prior, MD, a professor of endocrinology at the University of British Columbia. "People who are touting this method say, 'Well, women years ago didn't get their periods as much as we do now,' but it isn't the same thing." In the old days, women didn't get their period as often because they were pregnant or breastfeeding, thus their lifetime estrogen levels were lower than today.

Prior's colleague, Christine Hitchcock, PhD, researches menstrual cycles and ovulation. She worries that we also don't know if continuous birth control could affect fertility. "The use of extended birth control pills is suppressing a complex, intricate hormonal system," she says. "There are no long-term data to show whether changing the schedule of birth control affects how fast your periods come back when you go off, whether they come back, and your level of fertility."

Westhoff says such concerns are not borne out by research. "There have been numerous studies, both in the trials for Seasonale and other kinds of continuous regimens, that do include how long it takes to cycle and get pregnant, and the answer is there's no noticeable delay," she says. "I have no crystal ball, but in all the data we have so far, the cycle returns to normal with continuous birth control just as it does with regular oral contraceptives."

In fact, the National Women's Health Network, a women's health advocacy group that was among the earliest critics of hormone replacement therapy, does not see significant concerns with Seasonale. "Of course, we have a lot more data on regular pills. Our concern is somewhat less, though, because it's the same synthetic hormones that women have been taking for many decades for oral contraception," says program and policy director Amy Allina.

The Network does urge the makers of Seasonale and similar regimens to take care how they promote the new pill. "We've heard some people saying things like it's unnatural to get your period so much, it's not good for you, and suppressing your period is better," says Allina. "We feel strongly that that's a bad message for women to get. Putting aside the small group of women who really do have medical problems around menstruation, this is a matter of preference and convenience. We're all for convenience for women who find menstrual suppression appealing, but they should get information that helps them choose on that basis."