L-Theanine vs Lion's Mane

for cognition

Stronger evidence: tie

Stronger effect: L-Theanine

Safety: L-Theanine carries a minor interaction; Lion's Mane has none recorded.

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

grade C moderate certainty

improves attention and reduces distraction, especially combined with caffeine

100–200 mg, adults

grade C low certainty

early, small studies suggest a modest cognitive effect

~1 g/day, adults

sources: PMID:20000107 · PMID:00000010