Many women dont have any problems with hormonal birth control—whether its a pill, a ring, or a shot—but some do experience side effects. "Most are what I call ‘nuisance side effects," says Anne Foster-Rosales, MD, chief medical officer for Planned Parenthood Golden Gate and a professor at the University of California, San Francisco.

Those include headache, nausea, breast tenderness, or spotting between periods. Even though the side effects are mild, "some women are so annoyed by it that theyll discontinue using that method," says Dr. Foster-Rosales. (She adds, however, that women who get migraines with an aura—meaning that they see spots or lights—should not use combined progestin-estrogen hormonal methods.)

I Ditched Acne by Switching Birth Control


A marathon runner gets serious about side effects from the Pill Read moreMore about hormonal birth control

Other side effects are more than annoying. Depression or mood swings are widely reported, and some say the Pill lowers their sex drive. "For some women, the Pill does affect libido," says Hilda Hutcherson, MD, an ob-gyn professor at Columbia University.

A 2006 Boston University study found the change in libido lasted for months after women stopped the Pill. Other women, however, report increased libido while on hormonal birth control.