Background: The United States is increasingly recognizing period product insecurity, insufficient access to menstrual products and limited private spaces for managing menstruation due to financial constraints, as an issue impacting the well-being and dignity of Americans. One strategy to address period product insecurity has been distributing free period products via period supply banks. The outcomes of period product distribution outside the school setting are absent from the literature. Objectives: This study, a formative evaluation of the free period product distribution efforts of the Alliance for Period Supplies, aims to identify (1) characteristics of individuals receiving products from period supply banks and their experiences of period product insecurity and (2) health and social outcomes experienced by recipients of free period products. Design: Survey data collection occurred at two points: baseline and one-year follow-up. All study participants provided verbal consent. Methods: Between Fall 2018 and Spring 2020, 1863 baseline and 80 follow-up surveys were administered. Participants received free period products for themselves and/or a household member from one of 20 participating Alliance for Period Supplies period supply banks directly or from one of their 64 partner agencies. Results: At baseline, 72.4% of participants had to choose between buying period products and another basic need. One year after accessing a period supply bank, 36.3% of participants reported this experience (p = 0.018). Participants reported at baseline, on average, 7.8 days in the past year of avoiding seeing others, canceling appointments, or skipping work or school because they did not have access to period products. At follow-up, this was reduced to 1.2 days, on average, t (68) = 2.214, p < 0.05. Conclusion: Period supply banks play an essential role in facilitating access to period products and the resulting benefits. Our study highlights the need for sustainable, well-funded policies and interventions to address period product insecurity effectively in society. Plain Language Summary: How people in the United States benefit when they get free period products from a period supply bank Why we did this study: In the United States, many individuals cannot afford to buy period supplies and the other stuff they need to live. Period supply banks want to help by giving them free period products. Researchers do not know if getting free period products is helpful for individuals. What we wanted to learn: The Alliance for Period Supplies is a membership program for period supply banks. We wanted to learn about the individuals who get free period products and whether getting them was helpful. What we did: For a year, starting in Fall 2018, we asked 1863 individuals to fill out paper surveys. A year later, we asked 80 of those same individuals to fill out a second survey. We asked participants to take the survey if they got free period products from a period supply bank for themselves or someone they live with. Individuals only participated in the study if they told us they wanted to. What we learned: Individuals who cannot afford period products must navigate difficult decisions between purchasing products or choosing other basic needs. Providing free products through a period supply bank has lessened the burden on these individuals, reducing the number who had to choose. Individuals unable to afford period products may sometimes opt out of going places they want to go for pleasure or miss important events, like work or school, because they do not have period products. Getting free period products has eased these challenges, letting individuals participate more fully in activities and engagements without worry about period products. Why is this important: Period supply banks are essential places where individuals receive free period products. The period supply banks need more individuals, including our government, to donate period supplies or money to buy them so they can help more individuals. [ABSTRACT FROM AUTHOR]