There are several birth control pills on the market that allow women to have short, infrequent bleeding. The newest of these pills, Lybrel — approved last week by the US Food and Drug Administration — stops periods entirely as long as a woman takes it.
In clinical studies, women have taken Lybrel for one to two years, according to Dr. Amy Marren, director of clinical affairs for the manufacturer, Wyeth Pharmaceuticals. As soon as a woman stops taking Lybrel, a combination of estrogen and progestin, she gets a “withdrawal bleed,” which is not a true period because no ovulation has occurred.
While advocates of menstrual suppression claim that birth control pills that reduce periods to once every three months or once a year are a welcome lifestyle choice, critics worry about safety. In particular, said Judy Norsigian , executive director of Our Bodies, Ourselves, the Boston-based health advocacy group, is the fact that “there are no longterm safety data.”
Moreover, some women are ambivalent about losing periods. Two studies by nurse-researcher Linda C. Andrist , an associate professor at the MGH Institute of Health Professions, suggest that slightly more than half of women would choose not to menstruate every month. But many others see their monthly periods as symbols of fertility, normalcy, and health, Andrist said in an e-mail.
The package insert cautions that “because regular monthly bleeding does not occur on Lybrel, an unexpected pregnancy may be difficult to recognize.” Lybrel is comparable to other low dose contraceptives at preventing pregnancy.
As with all birth control pills, the period-stopping pills may lower levels of available testosterone, thus diminishing libido. The long-term pills can also trigger considerable breakthrough bleeding, said Dr. Alan Altman , a Brookline menopause specialist. “This pill doesn’t add much to existing birth control options,” Altman said.