By Mary Margaret Olohan, Daily Caller - Using birth control is linked to having a smaller region of the brain that affects hormones, sexual behavior, and more, a study released Thursday found… The study, which examined the effects of oral contraceptive pills (OCP) on the hypothalamus region of the brain, found that women who use the birth control have a smaller hypothalamus size than women who don’t use it… The hypothalamus plays a vital role in releasing hormones, regulating body temperature, maintaining daily physiological cycles, controlling appetite, managing sexual behavior, and regulating emotional responses.