Rhodiola vs Iron
for energy / fatigue
Stronger evidence: Iron
Stronger effect: Iron
Safety: Rhodiola carries a uncertain interaction; Iron has none recorded.
For energy / fatigue, Iron has the stronger evidence grade.
Rhodiola
grade C low certainty
small reductions in fatigue in stressed adults; studies are short and small
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)
sources: PMID:00000031 · PMID:10000007