For women of reproductive age, moods can shift depending on the moment. Some days you feel energized and ready to conquer life’s toughest obstacles, while others your clothes feel tight, your partner is getting on your last nerve, and you swing between sorrow and rage at the smallest provocation. To no one’s surprise, fluctuating hormones are usually the culprit for this type of mood melodrama. “Estrogen, progesterone, cortisol, and serotonin levels fluctuate depending on the time of the month,” says Maureen Cernadas, MD, a gynecologic surgeon with Saint Peter’s Healthcare System in New Jersey.