Why Are Migraines More Common in Women? A Biological and Sex-Based Perspective
Author: Dr. Meghan J. Chenoweth, PhD, University of Toronto | Editors: Tashi Stampp and Romina Garcia de leon (blog coordinators)
Published: May 15th, 2026
Migraines affect women substantially more than men. Why may that be? What biological factors might explain this difference?
We know that sex differences in the prevalence of migraine begin to emerge in puberty, with females disproportionately affected. We also know that hormonal changes can trigger migraine. These observations tell us that sex hormones are likely to represent a key biological factor in migraine risk. In addition to sex hormones, large-scale genome-wide association studies of migraine are demonstrating that genetic factors also play a key role in migraine susceptibility. We are currently investigating whether any of the genetic risk factors for migraine differ between women and men, and whether genes and hormones interact to further shape migraine risk.
How do hormonal changes influence the risk of migraines? For instance, why do some people notice migraines beginning around puberty or intensifying during menstruation, pregnancy or menopause?
Reproductive transitions, which are accompanied by significant hormonal changes, mark key shifts in migraine risk. Sex differences in the prevalence of migraine begin to emerge in puberty, with adolescent girls being disproportionately affected. Among women, the risk for migraine peaks in the third decade of life, followed by a gradual taper and sharp decrease post-menopause when ovarian hormones stabilize. Pregnancy is frequently associated with a transient improvement in migraine symptoms, followed by recurrence or worsening post-partum. These observations, alongside the existence of pure menstrual migraine (only occurs around the menstrual cycle) and menstrual-related migraine (occurs at any time but is worsened around the menstrual cycle) strongly suggest a female sex-sterioid influence on migraine.
What are health scientists beginning to uncover about the role genes may play in migraine risk for women?
We know from twin and family-based studies that migraine is 35-60% heritable, indicating that there’s a substantial genetic component to its etiology. One of my doctoral students, Simran Sandhu, is actively looking into whether there might be sex differences in the genetic influences on migraine risk. Simran is leveraging data from the UK Biobank, a cohort of around 500,000 British adults, to detect migraine risk genes, particularly in females. So far, we have identified several regions of the genome that harbour genes with significant associations with migraine in females, only some of which overlap with males. Simran is finding that many of the risk genes also associate with cardiovascular traits, which is interesting in light of the observed link between migraine and cardiovascular disease. Some of the migraine risk genes also showed associations with female-specific traits like endometriosis and age at menarche (age at first period), which again highlights the important role that sex hormones play in migraine.
Migraines and anxiety often occur together. Based on your research projects so far, do we know why these two conditions may be closely linked?
We think that the link between migraine and anxiety may be partially explained by shared genetic risk factors. For instance, using data from the UK Biobank, we found that migraine and anxiety show some degree of genetic correlation. Moreover, the largest genome-wide association study of anxiety disorders, published earlier this year, showed that there is a significant genetic overlap between anxiety disorders and migraine, again pointing at a shared genetic component. It’s important to stress, however, that there is no ‘migraine risk gene’ or ‘anxiety risk gene’- these are complex traits with many genes and variants contributing to the overall risk for the disorder. We must also consider the role of environmental and social risk factors, like adverse childhood experiences, which are known to increase the risk of experiencing migraine and anxiety both in childhood and later in adulthood.
Looking ahead with respect to progressing women’s healthcare in Canada, how could research on sex and genetic differences help improve migraine treatment?
Genome-wide association studies of migraine have already uncovered genes associated with migraine risk that are targeted by migraine treatments. One such example is the gene encoding calcitonin gene-related peptide, CGRP. Over the last eight years, seven novel migraine-specific medications that act on the CGRP pathway (i.e. the “gepant” class of medications, as well as the anti-CGRP monoclonal antibodies) have been approved by Health Canada. By digging deeper into the genetics of migraine, we anticipate being able to identify novel drug targets in the future. In addition, given the wide inter-individual variability in response to migraine treatment, research into sex and genetic differences may also support the development of personalized treatments. We hope that our work will lay the groundwork for future interventional studies that take a precision medicine approach, ultimately improving migraine care for all Canadians.
