It's a neurological disease, and the trigger is the estrogen drop, not the level. Rising estrogen quiets the brain's pain pathways; falling estrogen sets attacks off ¹. That's why a girl before puberty and a woman well past menopause, both at steady low estrogen, are mostly spared. It's the swing that hurts ². The headache itself runs on a nerve chemical called CGRP, which is what the newest prevention blocks.

One in three women gets migraine in her lifetime; among men it's one in seven ³. It peaks in the thirties and is the single leading cause of disability in women aged fifteen to forty-nine, ahead of depression, anxiety, and back pain ⁴. Roughly a quarter to a third have aura, and aura roughly doubles baseline ischemic-stroke risk on its own ⁵. That's the subgroup where contraception choice actually matters.

The whole thing turns on getting three answers on the record. Take these to a clinician who opens the eligibility criteria.

What treatment buys you. A CGRP injection shows benefit within four to twelve weeks; the STRIVE data cut migraine days by about 3.7 versus 1.8 on placebo, with half the treated group losing at least a third of their attack days ⁸. Fremanezumab, galcanezumab, and atogepant land in the same range ⁹. Four or five women in ten respond strongly to the first drug they try; most of the rest land somewhere good on the second or third. In felt terms: the Tuesdays you couldn't commit to come back onto the calendar.

Life stage rewrites the plan. About four in five women improve during pregnancy, most by the second trimester ¹⁰, though aura remits less reliably and attacks return within a month postpartum. Perimenopause is usually the worst stretch, with high-frequency headache running about half again as common then ¹¹. If hot flashes push you toward HRT, ask for a transdermal estradiol patch, which gives steadier levels than oral pills. After menopause about two-thirds of women ease off for good.