Objective: To investigate variation in early maladaptive schema (EMS) domains between day 1 and day 15 of menses among Lebanese female university students and assess factors potentially responsible for this variation, as well as the impact of EMS on premenstrual symptoms.Methods: This cross-sectional study enrolled 84 female participants between June and September 2020. The study consisted of interviewing participants (questionnaire 1) on the first day of their menses and then contacting them 15 days later to complete the follow-up survey (questionnaire 2).Results: Lower means of emotional deprivation, social isolation, defectiveness, and negativity were found on day 15 compared to day 1. Older age was significantly associated with a decrease in punitiveness on day 15 (P = .012). Furthermore, higher anxiety was significantly associated with increased emotional deprivation (P = .024), self-sacrifice (P = .008), unrelenting standards (P = .005), entitlement (P = .025), and approval seeking (P = .013) on day 15. Higher depression was significantly associated with increased emotional deprivation (P = .033), defectiveness (P = .04), failure (P = .043), dependence (P = .042), and subjugation (P = .048) on day 15. Higher stress was significantly associated with an increase in vulnerability (P = .017), unrelenting standards (P = .002), negativity (P = .024), and punitiveness (P = .008) on day 15. Moreover, having a monthly income compared to not was significantly associated with decreased emotional deprivation (P = .015), abandonment (P = .029), defectiveness (P = .039), failure (P = .033), dependence (P = .039), subjugation (.018), and punitiveness (P = .014) on day 15. Finally, higher physical activity was significantly associated with an increase in self-sacrifice (P = .03) on day 15.Conclusions: Potential treatment with schema therapy must be offered by experienced psychologists to eligible patients to minimize the apparent detriment caused by EMS to interpersonal relationships, social interactions, lifestyle, work performance, emotional well-being, and overall health-related quality of life.