PURPOSE OF REVIEW: Menstrual bleeding is a regular, common occurrence in a substantial portion of the population. Menstruators may use more than 10,000 menstrual products over the lifetime. Given the potential for environmental chemicals in menstrual products to be absorbed by the vulvar and vaginal epithelium into systemic circulation, we reviewed the available data on menstrual products as a source of environmental chemical exposure. RECENT FINDINGS: Nearly two dozen studies have been conducted measuring environmental contaminants in menstrual products; all have detected environmental chemicals but had discrepant conclusions on exposure risks. Only three human studies have investigated menstrual product use and environmental chemical concentrations and all observed associations. Detection of environmental chemicals in menstrual products, in combination with challenges of exposure assessment, scarcity of human studies, and the exceedingly common occurrence of menstrual bleeding, motivates the need for further research. We provide recommendations to move this field forward.

PURPOSE OF REVIEW: Menstrual blood loss, a common physiologic occurrence, provides an excretion route for per- and polyfluoroalkyl substances (PFAS) since these chemicals are bound to proteins in blood. To increase awareness of this relationship in environmental epidemiology, we reviewed the available epidemiologic data on menstrual bleeding and PFAS concentrations. RECENT FINDINGS: Initial epidemiologic studies reported generally higher PFAS concentrations in men, menopausal women, and those with a history of hysterectomy compared to premenopausal women. Although subsequent studies investigating menstrual cycle characteristics observed somewhat discrepant results for menstrual irregularity and cycle length, consistent associations have been observed between heavy menstrual bleeding and lower PFAS concentrations. This review highlights the important role of menstrual bleeding on the excretion of PFAS. Given the high prevalence of menstrual bleeding in the population and the implications for environmental epidemiology, we provide recommendations to move this field forward.