Brain Supplements: What the Research Shows and How Strong It Is

Some ingredients show small effects in some groups, and none has shown it can protect against dementia.

NCCIH's science summary reviews the field and reaches a cautious conclusion. A trial of more than 3,000 older adults found ginkgo did not lower dementia incidence or slow decline. A Cochrane review found no benefit of omega-3 supplements on cognition in older people without dementia. Evidence on curcumin is too limited, and B vitamins have not been shown to help over the short term. (NCCIH, Supplements and Cognitive Function: What the Science Says)

Against that backdrop, small positive findings for single ingredients in healthy adults are modest. That does not make them worthless. It means expectations should match the data.

It has the longest trial record of the five, and the record is still modest.

A meta-analysis of nine placebo-controlled trials with 518 people, all lasting 12 weeks or longer, found a faster Trail B test by about 18 milliseconds and shorter choice reaction time. The authors concluded bacopa may improve speed of attention and said a large head-to-head trial is still needed. A 2025 trial of a branded extract measured cognition, stress and fatigue in healthy adults over 12 weeks. (Kongkeaw 2014, Bacopa meta-analysis) (Lopresti 2025, Bacopa 12-week trial)

A 2026 network analysis of 29 trials with 2,107 healthy adults found high-dose bacopa, 600 mg a day or more, improved working memory against placebo and against ginkgo. It found no differences for sustained attention, selective attention or processing speed. The authors noted that the lack of direct comparisons limits the strength of the evidence. (Tiemtad 2026, Bacopa vs ginkgo)

Two cautions follow. These were healthy adults, not people with dementia. And the extracts were standardized products at specific doses, which a capsule with 200 mg may not match.

The two non-herbal ingredients are the least certain on memory.

Branched chain amino acids are the largest line on the label, at 540 mg of the 1,030 mg total. A 2026 systematic review of eight studies with 353 people found that five reported no significant change in cognitive function and three reported improvement, with effects depending on dose, duration and health status. Some studies even hinted at harm, and the authors asked for larger, stricter trials. A separate review explains that large neutral amino acids compete for entry to the brain, so loading one group can lower others. (Majid 2026, BCAA systematic review) (Fernstrom 2013, large neutral amino acids)

L-theanine, at 100 mg on the label, shows a different profile. A 2025 meta-analysis of 50 reviewed trials pooled 15 and found theanine alone beat placebo on choice reaction time in the first hour, though the confidence intervals often left the size and direction uncertain. The trials that used 200 mg were twice the label amount. In short, theanine looks like a calming, short-term ingredient, which is a different job from long-term memory. (Payne 2025, L-theanine meta-analysis) (Hidese 2019, L-theanine 200 mg)