Perimenopause library · Foundations

What perimenopause is — and what STRAW actually staged

Updated 2026-08-24 · 2 min read

The Stages of Reproductive Aging Workshop (STRAW, 2001) proposed a shared seven-stage map of adult female reproductive life, anchored on the final menstrual period. STRAW+10 (workshop 2011, papers 2012) kept that anchor and simplified the bleeding rules using later cohort data.

On that map, the menopausal transition is two stages. Early transition (stage −2) is a persistent change in cycle length of seven days or more. Late transition (stage −1) is amenorrhea of 60 days or more, or two skipped cycles. Late transition often lasts one to three years, and FSH is often higher, but STRAW does not diagnose an individual from a single blood test.

Clinical menopause is twelve months of amenorrhea after the final menstrual period. STRAW prefers “menopausal transition” in scientific writing. “Perimenopause” is the patient-facing term and usually includes the early years after menopause as well.

The Massachusetts Women’s Health Study and later reviews put median age at menopause near 51.4 years, with an average of about four years in the transition and a wide individual range. STRAW+10 said the staging system can be applied regardless of age, ethnicity, body size, or lifestyle — which is a research recommendation, not a promise that every body will look the same.

If your bleeding pattern is sudden, very heavy, or happens after you have already gone twelve months without a period, that is outside what this staging discussion can settle. Bring it to a clinician.

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