When should you start HRT — and can you start in perimenopause?

The recurring theme across the experts is the "timing hypothesis": hormone therapy started near menopause onset behaves very differently from therapy started a decade or more later. Initiated in the window — broadly within ~10 years of the final period, ages roughly 50-59 — is where the cardiovascular, bone, and brain benefits concentrate. Estrogen works better started early than as a late rescue.

You don't have to wait for periods to stop entirely. Hyman is explicit that hormone therapy is appropriate when perimenopausal symptoms begin, rather than waiting for a textbook definition of menopause (12 months without a period). Attia favors the same early-start logic, and his guest, urologist Dr. Rachel Rubin, goes further — arguing recent data challenges strict age cutoffs and that therapy should be offered more broadly, primarily for vasomotor symptoms, bone protection, and genitourinary symptoms.

There's a genuine open question at the other end: how long to continue. Attia flags long-term continuation well beyond the window as the biggest remaining unknown in the field, so "start early" is better supported than "stay on indefinitely." The November 2025 FDA label update echoes the early-start framing, noting benefits when therapy is initiated within about 10 years of menopause onset.

None of this is a green light to self-start. The window tells you when the benefit-to-risk math is most favorable, but the actual decision — candidacy, formulation, route, and dose — belongs with a menopause-trained clinician who knows your history.