Though some doctors have suspected that the Pill deadens desire based on anecdotal evidence gathered from patients, a recent and widely reported Boston University Medical Center study suggests why: The Pill raises the level of a certain protein in a woman’s body, which in turn blocks production of testosterone, the hormone linked to sex drive. The result, according to researchers: Not only can these lowered testosterone levels impair your ability to get aroused and become lubricated, but even when you stop taking the Pill, the effects can linger for several months or—eek!—longer.
The Pill in Action
Most women assume the Pill works by pumping you up with hormones, but it’s actually the opposite. “The two synthetic hormones in each pill, estrogen and progestin, regulate your body’s hormonal balance,” explains Susan Kellogg, PhD, director of sexual medicine at the Pelvic and Sexual Health Institute in Philadelphia. You don’t get pregnant because your ovaries are temporarily “shut down”—so they don’t release an egg each month, and sperm has nothing to fertilize.
But this hormonal change that the Pill induces can also contribute to vaginal dryness and lack of interest in sex—side effects that could be related to the possible testosterone blockage that showed up in the Boston study. “Your body’s not operating at full hormonal capacity,” says Kellogg.
What You Should Do
Since your libido is so complex, you shouldn’t hastily ditch your Pill pack in search of a better sex life, say most medical experts. “This is not a ‘one size fits all’ scenario,” says John Bancroft, MD, senior research fellow at the Kinsey Institute at Indiana University. “The Pill affects everyone differently.”
Even if you do notice a significant decrease in your libido, advises Kellogg, the first thing you should do is ask your doctor if you can try a different brand. There are about 20 varieties of Pills on the market, all with slightly different combinations of hormones and side effects. If you decide to experiment (with your doctor’s guidance, of course), you need to give your body at least three months to adjust to any given brand of Pill before you can accurately assess its ultimate impact on your libido.