Ashwagandha vs L-Theanine

for cognition

Stronger evidence: tie

Stronger effect: L-Theanine

Safety: Ashwagandha has the more serious interaction profile (moderate vs minor).

For cognition, the two are evidence-matched; the difference is in effect and safety.

grade C low certainty

preliminary improvements in memory/executive function; small trials

300–600 mg/day, adults

grade C moderate certainty

improves attention and reduces distraction, especially combined with caffeine

100–200 mg, adults

sources: PMID:42220661 · PMID:20000107