Can Magnesium help with fatigue?

Magnesium is often marketed for fatigue, but the evidence is nuanced. Magnesium deficiency can indeed cause fatigue, muscle weakness, and poor concentration, especially in older adults, people under chronic stress, or those taking certain medications. In such cases, supplementation may help. However, in individuals with normal magnesium levels, randomized controlled trials show no consistent benefit for general fatigue. The overall evidence is moderate: some studies support supplementation in deficient populations, but extrapolation to the general public is weak. Diagnosing deficiency is also challenging – serum magnesium can be normal despite cellular depletion. Consumer home tests (e.g., MyBody-X) can indicate trends but are not diagnostic. For persistent fatigue, other causes (iron deficiency, thyroid issues, sleep disorders) should be investigated first. Safety note: high doses of magnesium can cause diarrhea and electrolyte imbalances.