Supplements for cognition

Ranked by evidence grade. Nothing here is sold to you.

Caffeinegrade Ahigh certainty— reliably improves alertness, reaction time, and vigilance

Creatinegrade Bmoderate certainty— Meta-analysis of 16 RCTs (n≈492 adults): improved memory, attention, and processing speed; no significant effect on overall or executive function.

Lion's Manegrade Clow certainty— early, small studies suggest a modest cognitive effect

Ginkgograde Clow certainty— no reliable benefit for preventing cognitive decline in large trials

L-Theaninegrade Cmoderate certainty— improves attention and reduces distraction, especially combined with caffeine

Irongrade Clow certainty— improves attention/cognition when iron deficiency is present; no benefit if replete

Ashwagandhagrade Clow certainty— preliminary improvements in memory/executive function; small trials

Omega-3not well studiedvery-low certainty— not adequately studied for cognition in healthy adults