wellness-guides

Supplement Timing and Your Menstrual Cycle

Iron, magnesium, B6, and omega-3s may benefit different menstrual cycle phases. Here's what the evidence supports for supplement timing by phase, and where the claims outrun the data.

Supplement recommendations for the menstrual cycle range from evidence based (iron for documented deficiency) to speculative (elaborate phase by phase supplement rotations with no controlled trial support). This guide separates the supplements with meaningful evidence from the ones where the marketing has outpaced the science. This article is for educational purposes and is not medical advice. Consult a healthcare provider before starting any supplement, especially iron. Test iron levels before supplementing — excess iron is harmful. Iron: The Strongest Case The evidence: Menstruation is the primary cause of iron deficiency in people who menstruate. Blood loss depletes iron stores (ferritin) over time. Iron deficiency — even without anemia — produces fatigue, impaired exercise performance, reduced concentration, and cold intolerance. Who needs it: Anyone with ferritin below 30 ng/mL should discuss supplementation with a provider. Some practitioners use a threshold of 50 ng/mL for optimal function. A ferritin test, not just hemoglobin, is necessary to assess iron stores. Timing: Standard treatment is daily supplementation. For those who experience GI side effects from daily iron, al