Does the menstrual cycle affect hair and scalp health?

Introduction: Hair and scalp conditions are significant indicators of overall health and well-being, impacting quality of life in multiple domains, including emotional and social aspects. This international study assessed self-reported hair and scalp disorders in women aged 18–55 years and explored their associations with menstrual cycle regularity and phases. Methods: This cross-sectional observational study was conducted between January 13 and February 20, 2023, across 20 countries. A stratified proportional quota sampling ensured national representativeness. A digital questionnaire collected data on demographics, menstrual cycle characteristics, and 11 hair and scalp disorders, with additional details on the timing and persistence of these disorders. Women without recent menses, peri-menopausal, post-menopausal, and post-partum participants were excluded. Statistical analyses were performed using HARMONIE 1.7 software, with p<0.05 considered significant. Results: Among 20,001 surveyed women, 17,009 with active menses were included. The mean age was 34.49 ± 9.66 years. 58.8% of women reported regular cycles, while 41.2% had irregular cycles. Overall, 83% of participants reported at least one hair or scalp disorder. The most common conditions were itchy scalp (48.8%), dandruff (47.6%), and oily scalp (45.8%). Disorders were more prevalent in women with irregular menses; for instance, itchy scalp (55.9% vs. 46.6%) and dandruff (55% vs. 47.3%) were significantly higher (p<10^-3). Permanent conditions like diffuse hair loss and frontal alopecia were noted, while intermittent disorders showed higher prevalence during premenstrual and menstrual phases than in the peri-ovulatory phase. Conclusion: This study highlights the significant association between menstrual irregularities and hair and scalp disorders, emphasizing hormonal influences. These findings call for further research into targeted treatments addressing hormonal imbalances to improve women’s dermatological and overall well-being.

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