Hey girls, how would you like to get your period just four times a year? Think it's a pretty good deal, or would you hesitate to tamper with "the flow"? Well, a seasonal period is now one of your options.

The U.S. Food and Drug Administration recently approved Seasonale, a birth control pill that reduces your monthly periods to once each season while also preventing pregnancy.

Although some girls are hesitant to tamper with their bodies' natural functioning, others might be eager to reduce the annoyance of cramps, PMS and monthly trips to the drug store for feminine hygiene products. Plus, Seasonale is 99.7-percent effective at preventing pregnancy, when taken properly. (The typical-use rate is 92 percent.)

Old Pill, New Method

Seasonale, manufactured by Barr Laboratories, was introduced to consumers in September 2003. But Seasonale is basically the same birth control pill that has been around for a long time, according to Anita L. Nelson, MD, professor of obstetrics and gynecology at the David Geffen School of Medicine, University of California , Los Angeles. The manufacturers are simply prescribing a new way to use it.

"This isn't a new pill," Dr. Nelson explains. "It's just a new way of taking a pill that's been around."

Seasonale contains estrogen and progestin, the same hormones found in the better known 28-day birth control pill. The Seasonale package includes two different types of tablets: pink and white. The pink "active" tablet contains estrogen and progestin, which prevent a woman's ovaries from releasing an egg, so she cannot get pregnant. As long as a woman takes these hormones, she also skips her period.

In the traditional approach, women took three weeks of active pills, followed by one week of "placebos," which have no hormones and are used to keep the woman in the habit of taking a pill each day. This cycle allowed her to get a monthly period. With Seasonale, you take the active hormones for 12 weeks (84 days), followed by one week (7 days) of the white placebo pills. That reduces your period to once every three months.

Proceed With Caution

Like other birth control pills, Seasonale does NOT protect against sexually transmitted diseases, so to avoid infection, you have to use a barrier method of protection (like a condom), every single time you have sex.

And like other birth control pills, Seasonale can cause some side effects, including bleeding or spotting between periods. Smokers should steer clear of Seasonale, according to Laura Berman, Ph.D. and coauthor of For Women Only: A Revolutionary Guide to Overcoming Sexual Dysfunction and Reclaiming Your Sex Life. Cigarette smoking can increase the possibility of serious side effects of all oral contraceptives, including blood clots, stroke and heart attack.

"Seasonale can be taken by any non-smoking female trying to prevent pregnancy and to control her menstrual cycle," says Dr. Nelson. "The only formal age requirement would be menstruation and sexual activity. Women in their teen years experience some of the most powerful and painful menstrual periods and should also be allowed access to Seasonale."

Getting Started

You need a doctor's prescription to get Seasonale. It can cost anywhere from $35 to $125, depending on where you get it. For example, if you go to your primary health care provider, chances are you'll be billed for the visit and the supply of pills, so it will cost more. But if you go to a family planning clinic, like Planned Parenthood, you may only have to pay what you can afford. (This is known as paying on a "sliding-scale fee.")

Like any contraceptive, you have to use Seasonale correctly for it to be 99.7-percent effective. That means taking one tablet every single day, at roughly the same time each day. If you forget to take the pill, even for one day, you can get pregnant, assuming you're sexually active.

Weighing Your Options

All methods of birth control have pros and cons. For some, getting a period only four times a year just feels too weird.

"It's an unnatural means of altering a normal and healthy bodily function," says Heather, 18, of Houston, TX. "A normal female has her period roughly once a month. That's all there is to it. By taking a pill that alters the balance of hormones in the reproductive system, there's no telling what the long-term consequences will be. Personally, I'm not going to be a guinea pig."

But studies have shown that long-term use of the hormones contained in most oral contraceptives, including those in Seasonale, pose no long-term threats to a woman's health. Others see fewer periods as a real bonus.

"There is nothing wrong with making changes that will make the lives of women easier," says 15-year-old Mollie, of New York City. "This contraceptive gives girls less to think about and reduces stress."

Your Choice

Everyone is different. That's why you have to choose the contraceptive that best fits your lifestyle.

"Any woman who is interested in using Seasonale, whether because of the health options involved or simply because of convenience, should explore her options thoroughly with her doctor," advises Berman.

Editors' Note: For more on Seasonale, visit the official Web site or call 1-800-719-FOUR (3687).