6 Questions About Hormone Replacement Therapy Hormones have always been good at messing with us. They get a bad rap, but we need hormones to regulate all of our bodily functions, from hunger to emotions. During puberty, they transform many of us into moody, confused teenagers with a penchant for slamming doors and sulking. As we get older, our hormones can tell us precisely when we’d be getting our periods. During perimenopause, estrogen hormones decrease which can lead to an all-new set of hormonal woes: hot flashes, sleeplessness, weight gain, vaginal dryness, and mood changes, to name just a few.