Background: More than half of women of reproductive age in India are anemic. Anemia is associated with increased risk of preterm delivery, higher maternal mortality and contributes to fatigue, which affects women’s work productivity. The World Health Organization (WHO) recommends daily oral iron and folic acid (IFA) supplements during pregnancy and weekly supplements for women of reproductive age. Government programs and global donors have distributed and promoted IFA supplements in India for over four decades. However, initial intake and compliance remain inadequate. Objectives: This protocol describes the formative research phase of a larger study, which will test, through a randomized controlled trial, the hypothesis that a social norms-based behavioral intervention in Odisha, India will improve uptake of IFA supplements and reduce anemia among reproductive age women as compared to usual care. The focus of this paper is on the formative research required to develop a sound intervention. We will examine socio-normative barriers to and facilitators of IFA supplement uptake. Methods and analysis: Based on the Theory of Normative Social Behavior, we will adopt a mixed-method, multilevel approach. We will collect data using focus groups, in-depth interviews, observations, Rapid Participatory Ethnographic Evaluation and Research (PEER) techniques, and perceptual mapping methods. Our sample includes reproductive age women (pregnant and not pregnant), their husbands, their mothers/in law and key stakeholders. After analyzing the results, we will hold a convening in India to collaboratively design the intervention. Following the intervention design, we will test components of the intervention, gather user feedback and tweak as necessary. Additionally, to improve adoption and sustainability of the intervention, we will conduct policy dialogue with stakeholders throughout the formative research. Impact: This study will contribute to the social norms and behavioral intervention research and inform policymakers about th