Supporting files for a prospective longitudinal study investigating the use and acceptability of reusable menstrual underwear by internally displaced women in Somalia. The study was comprised of 295 women selected from a random sample who received menstrual underwear with bags for washing and drying. Surveys were conducted by MedAir at and within 12 months of distribution to capture demographics, menstrual practices, use of the menstrual materials, and acceptability or issues with the materials. Data collection took place in July 2024 and from April to May 2025. This item consists of a Stata DO-file written to analyse factors associated with the use of the menstrual underwear and a dataset codebook that outlines variables used in the analysis. Data that supports the study findings are owned by MedAir and was used under licence for the current study. Researchers may access this data by contacting MedAir directly.