What to take for energy / fatigue

Graded by the strength of the evidence — strongest first. Nothing here is sold to you.

Irongrade A— reliably reduces fatigue when iron deficiency / IDA is present; no benefit when iron-replete

CoQ10grade A— Meta-analysis of 13 RCTs (n=1,126) found CoQ10 supplementation significantly reduced fatigue scores versus placebo (Hedges' g = -0.398, 95% CI: -0.641 to -0.155, p = 0.001). Benefits were consistent in healthy and diseased participants, and greater reductions were associated with higher daily doses and longer durations. The effect was significant for CoQ10-only formulations but not CoQ10 compounds.

Caffeinegrade B— reduces perceived fatigue; tolerance develops with regular use

Ashwagandhagrade B— Ashwagandha supplementation was more efficacious than placebo for improving fatigue/recovery variables in healthy individuals.

Rhodiolagrade C— small reductions in fatigue in stressed adults; studies are short and small

CoQ10grade C— limited evidence for general fatigue; clearer in specific conditions (e.g., statin myalgia, mitochondrial disorders)

Vitamin B12grade C— corrects fatigue when B12 deficiency is present; no energy benefit in replete people

Creatinegrade C— may reduce mental fatigue, especially under sleep deprivation or stress

Rhodiolagrade C— may reduce stress-related fatigue; trials small and heterogeneous

NMNnot well studied— not adequately studied for fatigue/energy outcomes in humans