Iron vs CoQ10

for energy / fatigue

Stronger evidence: Iron

Stronger effect: Iron

Safety: No notable interactions recorded for either.

For energy / fatigue, Iron has the stronger evidence grade.

Iron

grade A high certainty

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

18–65 mg/day, iron-deficient adults (esp. menstruating women)

CoQ10

grade C low certainty

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

100–200 mg/day, adults
sources: PMID:10000007 · PMID:10000009