Most of what women call 'menopause' is actually perimenopause — the 4–10 years before your last period. Once cycles have stopped for 12 months, you're post-menopausal. Different stage, different testing, different protocol.
Perimenopause: the swing years
Progesterone falls first, then estradiol starts swinging wildly. FSH climbs as the brain works harder. Symptoms are often more intense in perimenopause than in menopause itself — the volatility is what hurts.
Menopause: the new baseline
Once cycles have stopped for 12 months, the system settles at low estradiol and progesterone. FSH stays high. The body adjusts — but bone density, cardiometabolic risk and thyroid drift become the things worth tracking.
What each stage needs to test
Perimenopause: FSH, LH, estradiol, progesterone (cycle-day timed), AMH, full thyroid. Menopause: FSH, estradiol baseline, full thyroid, lipids, HbA1c, insulin, vitamin D.