It is not unusual hormones. Women with PMDD have the same estrogen and progesterone as everyone else on a given cycle day ¹; what differs is a heritable difference in how the brain reads the normal monthly swing ². Shut off the cycle and symptoms vanish; add either hormone back and they return, but only in women who have PMDD ³. So "balancing your hormones" with progesterone loads the trigger and backfires.

The tell is the calendar. Symptoms hit in the luteal phase, the two weeks after ovulation, and clear by day four of your period. That pattern separates PMDD from bipolar II and borderline, which cycle too but ignore the calendar ⁴. First-line treatment is an SSRI, and the evidence is unusually clean: across 31 trials, response runs about 60 to 70% ⁵. The useful oddity is speed: SSRIs work in days here, not the six weeks they take for depression, so one luteal phase tells you if it helps.

The diagnosis comes before the prescription; that is the step everyone skips.

Adjuncts worth adding: PMDD-specific CBT, whose effect outlasts the course ⁹, aerobic exercise around 150 minutes a week ¹⁰, and calcium 1,200 mg/day ¹¹.

The first treated luteal phase is the tell. On an effective SSRI, most responders feel that week as recognisably different within days, the mood floor no longer dropping ¹². By the third cycle the week you used to brace for is a normal one, and the energy, focus, and sleep the bad weeks ate come back. This is management rather than cure: skip the pill and a bad luteal phase returns within a cycle, and PMDD ends for good only at menopause.