Caffeine vs Rhodiola

for energy / fatigue

Stronger evidence: Caffeine

Stronger effect: Caffeine

Safety: Rhodiola has the more serious interaction profile (minor vs uncertain).

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

grade B moderate certainty

reduces perceived fatigue; tolerance develops with regular use

40–200 mg

grade C low certainty

small reductions in fatigue in stressed adults; studies are short and small

sources: PMID:00000021 · PMID:00000031