FDA OKs 'No-Period' Birth Control Pill
Lybrel Is 1st Oral Contraceptive Designed to Stop Menstruation
Eliminating Menstrual Cycles continued...
Normally, says Goldstein, a rise in hormones linked to ovulation causes the
lining of the uterus to thicken in anticipation of a fertilized egg. If
fertilization does not occur, hormone levels drop and the lining is shed in the
form of menstrual blood. Oral contraceptives, however, change that
"The pill shuts down your normal hormone production and replaces it with a
very tiny amount, so there is no buildup of the uterine lining," says
Goldstein, a professor at NYU Medical Center in New York City. Without a
lining, there is no shedding, so the bleeding that occurs when you stop the
pill is a "withdrawal bleed caused by a drop in hormones," explains
Goldstein tells WebMD that the monthly bleeding that occurs during pill use
is unnecessary, so avoiding it -- the way you can with Lybrel -- should have no
impact on health. Moreover, Goldstein says the menstrual cycle and fertility
should return soon after stopping this pill, much the way it does with other
In at least one study conducted by Wyeth and presented at the 2006 annual
meeting of the American College of Obstetricians and Gynecologists, 99% of 187
women taking Lybrel for one year either returned to menstruating or got
pregnant within 90 days after stopping the drug.
Long-Term Safety Questioned
The FDA has asked Wyeth to do a postmarketing study to see if the risk of
serious adverse events -- particularly blood clots -- is more common with
Lybrel than with traditional contraceptives.
"We don't suspect that there are going to be any surprises in terms of
long-term use of this product," Shames says.
Side effects of Lybrel are similar to other low-dose oral contraceptives,
including an increased risk of blood clots, particularly in smokers and women
over 35, and breakthrough bleeding.
Perhaps more importantly however, cancer experts, like NYU's Julia Smith,
MD, are concerned about the lack of long-term data measuring the impact of
continuous-use hormones on the risk of breast and other hormone-fueled
"This is something that has not been carefully studied yet. We don't have
any evidence that there is a problem, but we certainly have many instances in
the history of medicine where problems only showed up at a much later date
after long-term exposure and widespread use," says Smith, director of the Lynne
Cohen Breast Cancer Preventive Program at the NYU Cancer Institute.
Moreover, she tells WebMD, "When you tamper with the way the body works
naturally you can't predict long-term outcome until you study long-term
outcome. And right now we don't have that data."
According to spokeswoman Natalie deVane, Wyeth has conducted large clinical
trials evaluating efficacy and safety for one year, with a smaller subset of
women followed for a second year. For use beyond that point, they suggest women
turn to their doctor for advice.