Objective: Stimulant medications are the primary pharmacological intervention for ADHD, yet our understanding of how sex and gender impact stimulant treatment outcomes remains limited. Clinical guidelines do not differ for female and male individuals despite possible sex and gender-related differences in effectiveness, adverse events, and pharmacokinetics. This theoretical framework identifies five key knowledge gaps relating to sex and gender effects in stimulant treatment. Method: We investigate the stimulant treatment trajectories of girls and women with ADHD from diagnosis and prescription to daily use and outcomes. We examine the impact of reproductive life transitions and hormonal fluctuations and their interactions with gender socialization and gendered expectations on treatment effectiveness, stigma, and adherence. Results: By synthesizing existing literature, proposing testable predictions, and suggesting future research directions, we highlight the urgent need for studies that systematically investigate these factors. Conclusion: Addressing these gaps could significantly improve treatment outcomes for girls and women with ADHD, particularly during biological and gender role transitions.developmental