Combined birth control pills that contain natural estradiol or an estradiol ester (e.g., estradiol valerate) include: * Estradiol valerate and cyproterone acetate (brand name Femilar) – introduced in Finland (only) in 1993 * Estradiol valerate and dienogest (brand names Qlaira, Natazia) – introduced in Europe in 2009 and the U.S. in 2010 * Estradiol and nomegestrol acetate (brand name Zoely) – introduced in Europe in 2011