Supplements for cognition
Compared by effect and evidence certainty. Cost is not currently assessed, and nothing here is sold to you.
Caffeinegrade Ahigh certainty— reliably improves alertness, reaction time, and vigilance Safety: minor — Commonly paired; L-theanine is said to smooth caffeine’s jitter. Low-stakes.. Cost: not assessed. Evidence gaps: no major structured gap flagged; review the claim limitations.
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. Safety: no modeled interaction found; coverage unknown, not proven safe. Cost: not assessed. Evidence gaps: population bounds not reported.
Melatoningrade Bmoderate certainty— Meta-analysis of RCTs in older adults with cognitive impairment: melatonin produced a modest improvement in cognition (MMSE +1.8 points) and total sleep time (+12.4 minutes), with a small reduction in neuropsychiatric symptoms. The authors conclude effects approach — but fall short of — definitive clinical efficacy, with substantial heterogeneity between trials. Safety: uncertain — Melatonin with an SSRI: possible additive sedation; evidence is thin.. Cost: not assessed. Evidence gaps: no major structured gap flagged; review the claim limitations.
Lion's Manegrade Clow certainty— early, small studies suggest a modest cognitive effect Safety: no modeled interaction found; coverage unknown, not proven safe. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Ginkgograde Clow certainty— no reliable benefit for preventing cognitive decline in large trials Safety: serious — Ginkgo has antiplatelet activity; with warfarin it may increase bleeding risk.. Cost: not assessed. Evidence gaps: studied dose not reported; population bounds not reported; certainty or evidence strength remains limited.
L-Theaninegrade Cmoderate certainty— improves attention and cuts down distraction, especially paired with caffeine Safety: minor — Commonly paired; L-theanine is said to smooth caffeine’s jitter. Low-stakes.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Irongrade Clow certainty— improves attention/cognition when iron deficiency is present; no benefit if replete Safety: no modeled interaction found; coverage unknown, not proven safe. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Ashwagandhagrade Clow certainty— preliminary improvements in memory/executive function; small trials Safety: moderate — Ashwagandha with an SSRI may carry additive sedative/serotonergic risk; evidence is limited.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Vitamin Dgrade Clow certainty— Systematic review and meta-analysis: lower vitamin D levels are associated with poorer cognition and higher dementia risk. The association is mostly observational; supplementation trials have not established that raising vitamin D improves cognition. Safety: minor — Magnesium is a cofactor in vitamin D metabolism; the two are complementary.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Turmericgrade Clow certainty— Systematic review: curcumin may modestly benefit some cognitive domains in older adults, but effects are inconsistent across domains and trials are small, with bioavailability a recurring limitation. Safety: moderate — High-dose curcumin may have mild antiplatelet effects; caution with warfarin.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Rhodiolagrade Clow certainty— Review of Rhodiola rosea preparations: modest reductions in mental fatigue and small improvements in cognitive performance under stress in some trials. Studies are small and of low-to-moderate quality. Safety: uncertain — Rhodiola may have mild serotonergic activity; evidence with SSRIs is thin — treat as cautionary.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Magnesiumgrade Clow certainty— Systematic review of magnesium and cognitive health in adults: the evidence linking magnesium status or intake to cognition is limited and inconsistent, drawn largely from observational data, and the authors call for better-designed studies with repeated magnesium biomarkers before any conclusion. No demonstrated cognitive benefit from supplementation. Safety: minor — Generally fine with an SSRI; space about 2 hours apart.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.
Caffeinegrade Dvery-low certainty— Cochrane review, 13 RCTs, shift-work context: memory/attention improved, no verbal-skill benefit; high risk of bias flagged; mostly young people in simulated conditions, not real shift workers. Safety: minor — Commonly paired; L-theanine is said to smooth caffeine’s jitter. Low-stakes.. Cost: not assessed. Evidence gaps: certainty or evidence strength remains limited.