Ashwagandha vs Vitamin B12
for energy / fatigue
Stronger evidence: Ashwagandha
Stronger effect: Ashwagandha
Safety: Ashwagandha carries a moderate interaction; Vitamin B12 has none recorded.
For energy / fatigue, Ashwagandha has the stronger evidence grade.
Ashwagandha
grade B moderate certainty
Ashwagandha supplementation was more efficacious than placebo for improving fatigue/recovery variables in healthy individuals.
Vitamin B12
grade C low certainty
corrects fatigue when B12 deficiency is present; no energy benefit in replete people
RDA-to-high oral, adults
sources: PMID:33670194 · PMID:10000010