Progesterone 101

Jamie Gallagher, a board-certified family nurse practitioner and Menopause Society certified practitioner, explains progesterone’s roles beyond pregnancy and what happens as it declines during perimenopause. She describes progesterone as a calming, balancing hormone with receptors in the brain, uterus, breast tissue, and bone, noting its conversion to allopregnanolone and its effects on sleep, anxiety, irritability, and mood. She explains how falling progesterone—often before estrogen—can create “estrogen dominance,” contributing to heavy or irregular periods and intensified PMS/PMDD-like symptoms, and notes that micronized progesterone (Prometrium) may help in early perimenopause. She also clarifies progesterone vs synthetic progestins (e.g., MPA/Provera), highlighting that the Women’s Health Initiative used a progestin, not micronized progesterone, and that these differences matter when interpreting hormone therapy risks and benefits.00:00 Welcome and Recap00:48 Progesterone Beyond Pregnancy01:40 Calming Hormone Balance02:43 Brain Sleep and Anxiety03:27 Uterus Period Changes04:14 Breast Bone and Mood05:30 Perimenopause Symptom Timeline07:28 Progesterone vs Progestins09:45 Wrap Up and Disclaimer