Seasonale, the "extended cycle" pill approved in 2003, gives you only four periods a year. Lybrel, the continuous-use, "no period" pill, was approved in 2007. They work the same as regular birth control pills by preventing ovulation.
"Isn't it unnatural?" many women worry. Yes and no. Extended-use pills are not any more "unnatural" than other birth control pillsthe "period" you get with a regular monthly birth control pill isn't really a period, because you're not ovulating.
The new continuous pills appear to be a safe, effective, and convenient treatment option for endometriosis and for women who have debilitating periods, with severe cramps, mood swings, and the like.
"The extended-use pill is safe, reliable, and reversible," says Lee Shulman, MD, a professor at Northwestern University who sits on the board of directors of the Association of Reproductive Health Professionals. "When you're pregnant, you don't have a period," he says, and what these pills do is to suppress ovulation and convince your body that it's pregnanta natural state.