20/06/2025
Hormones and the Brain: If you (like me) are intrigued by this subject, have a read of this article. ✨️ Intuitively you may have recognised how you change over the month, MRIs showed just how in this study.
🧠Recent research has shown that hormonal fluctuations throughout the menstrual cycle induce significant, brain-wide structural changes—extending well beyond regions traditionally associated with reproductive function.
In a study led by neuroscientists, thirty women were monitored across their menstrual cycles using MRI scans and hormone measurements. The results revealed that both white matter microstructure and cortical thickness changed in sync with hormonal rhythms, affecting the entire brain—not just areas dense in hormone receptors, such as those in the hypothalamic-pituitary-gonadal axis.
These brain changes were closely tied to specific hormonal shifts. For instance, just before ovulation, when levels of 17β-estradiol and luteinizing hormone peak, participants exhibited alterations in white matter that may reflect enhanced information processing.
Similarly, follicle-stimulating hormone, which also surges pre-ovulation, was associated with increased gray matter thickness. After ovulation, rising progesterone levels correlated with increased brain tissue volume and a reduction in cerebrospinal fluid. These findings suggest that the brain’s structure is highly dynamic and closely attuned to reproductive hormone cycles.
Despite the menstrual cycle’s ubiquity—occurring roughly 450 times over a woman’s lifetime—research on its impact on brain structure has been limited. Most previous studies have focused on hormonal effects during specific cognitive tasks, rather than investigating structural brain changes.
This study highlights the need for deeper research into how these cyclical shifts may influence cognition, behavior, and mental health. While the exact effects on day-to-day functioning remain unclear, the findings lay important groundwork for exploring how menstrual cycles might contribute to both mental health conditions and cognitive resilience in women.
RESEARCH PAPER đź“„
Elizabeth J. Rizor et al, “Menstrual cycle-driven hormone concentrations co-fluctuate with white and gray matter architecture changes across the whole brain”, Human Brain Mapping(2024).
