Before choosing a magnesium form for fatigue, it’s crucial to assess the real cause. Iron deficiency, low B12 or vitamin D, thyroid disorders, depression/anxiety, sleep apnea, and insufficient calories/protein are often more common drivers. If diet is poor and inadequate magnesium intake is plausible, better-dissolving forms (citrate, chloride, lactate, aspartate; and in practice, chelated forms like glycinate) are frequently better tolerated. Oxide may cause more GI issues for some. Still, if “energy” is the goal, a holistic plan—sleep, caffeine timing, daylight exposure, movement, diet quality, and appropriate labs—usually delivers more impact than any single mineral.