Abstract Introduction: Dysfunctions in menstrual physiology significantly impact the quality of life, including mood changes, body image, infertility, and pregnancy complications. Light exposure may affect menstrual cycles and symptoms by influencing melatonin secretion. This systematic review aims to investigate the impact of sunlight exposure on menstrual cycle variability, particularly in women with cardiovascular conditions. Methods: Databases including Science Direct, PubMed, Google Scholar, SID, and MagIran were reviewed to identify studies examining the effect of sunlight on menstrual cycle changes. An initial search yielded 42 articles, with 9 duplicates removed. After applying inclusion and exclusion criteria, 17 articles were selected for detailed screening and analysis. Two researchers with experience in conducting systematic reviews evaluated the articles based on title, abstract, introduction, methodology, results, discussion, and references, identifying strengths and weaknesses. Ultimately, 7 articles met the criteria and were included in the review. Results: Out of the 42 initially identified articles, 7 studies met the inclusion criteria and were included in the review. Evidence indicates a relationship between light exposure, melatonin secretion, irregular menstrual cycles, menstrual cycle symptoms, and ovarian dysfunction. Research on the light-dark cycle's role in menstrual physiology has implications for managing menstrual disorders. Conclusion: Increased ovarian activity, including larger ovarian follicle size, higher ovulation frequency, and shorter menstrual cycles, is observed in summer compared to winter among women living in temperate latitudes. These findings have significant implications for women with cardiovascular conditions, suggesting that sunlight exposure may play a role in managing menstrual cycle variability and associated symptoms.