Objectives: The use of menstrual hygiene products and its effect on women’s health remains under studied. Patterns of menstrual hygiene product use and the rationale behind choices among Korean women aged 18-45 years were examined. Methods: This cross-sectional study was a part of the Korea Nurses’ Health Study. A total of 20,613 nurses participated, and 8,658 nurses participated in Module 7 which included a menstrual hygiene productsrelated survey. The data were collected through the mobile survey using a self-reported questionnaire.Participants’ use of menstrual hygiene products and related characteristics were analyzed using frequency (percentage) or mean (SD). Results: The most common types of menstrual hygiene products across all age groups were disposable menstrual pads (89.0%), followed by cloth menstrual pads (4.5%), tampons (4.2%), and only 1.6% used a menstrual cup. Disposable menstrual pads were the most common across all age groups, but in those aged under 30 years this was followed by tampon use (6%). The most important criteria when choosing a menstrual hygiene product was comfort for disposable menstrual pads (31.3%) and tampons (41.5%), natural ingredients or organic products for cloth menstrual pads (51.4%), and custom fit for the menstrual cup (50.7%). However, for all menstrual hygiene products (except cloth menstrual pads), there was a higher proportion of anxiety than perception of safety, and low awareness of toxic shock syndrome. Conclusion It is important for women to use menstrual hygiene products with confidence. More research is needed to better understand potential health effects of menstrual hygiene products.

The Korea Nurses’ Health Study (KNHS) is an ongoing, large-scale, prospective cohort study of women nurses, focusing on the effects of occupational, environmental, and lifestyle factors on the health of women. The first KNHS survey was performed in 2013-2014 (n=20,613). As of December 2023, 11 follow-up surveys have been conducted. Participants who were pregnant were asked to participate in the early pregnancy survey (n=2,179) and postpartum survey after giving birth (n=2,790). The main variables included socio-demographic, work-related, lifestyle, physical, mental, and women’s health factors. Blood, urine, and toenail samples were collected from a participant subgroup of the first survey (n=1,983). The subgroups of the second survey completed a food frequency questionnaire in 2019 (n=300) and 2021 (n=871). In 2020, a subgroup of the first survey answered a coronavirus disease 2019-related survey (n=975). To examine various health-related factors in young adults, new participants were added to the KNHS cohort in the 11th (n=1,000) and 12th (n=1,002) surveys. The KNHS cohort will help identify health and illness determinants in Korean women. Data can be accessed at https://coda.nih.go.kr/frt/index.do.