Creatine and the Menstrual Cycle: What the Science Says

Hormonal fluctuations throughout the menstrual cycle directly affect creatine metabolism. Estrogen and progesterone influence creatine kinase activity and phosphocreatine resynthesis rates. During the luteal phase (post-ovulation), research shows reduced sprint performance and recovery — periods when creatine availability may be lower. Consistent daily supplementation of 3-5g helps maintain stable creatine stores across all cycle phases, potentially reducing performance variability. Some researchers hypothesize that the neuroprotective effects of estrogen and creatine may be complementary, though more research is needed. For athletes who notice energy dips or increased fatigue in the luteal phase, creatine represents one of the few evidence-based nutritional interventions with documented impact on hormonal-phase performance.