GradedHealth

Nootropics: new review ranks bacopa above ginkgo for memory

A 2026 review of 29 trials found high-dose bacopa beat placebo and ginkgo on memory tests. But a 2025 trial found no benefit, and many studies are weak.

Published October 2026

Short answer

The best-tested options show modest benefits at most: bacopa for memory in some trials, caffeine and L-theanine for attention, creatine for memory in older adults. Findings conflict and prescription 'smart drugs' only nudge test scores. Evidence grade C (Limited). Network meta-analysis of 29 small randomised trials plus older reviews and trials; downgraded for inconsistent results, implausibly large effect sizes and high risk of bias across the field.

Key takeaways

  • A 2026 network meta-analysis of 29 randomised trials in healthy adults found high-dose bacopa (600 mg a day or more) improved working-memory scores compared with placebo and with ginkgo [1].
  • A 2025 randomised trial of 101 adults found 300 mg of bacopa a day for 12 weeks did not improve verbal learning, attention or working memory, so the memory evidence is mixed [2].
  • Prescription smart drugs did little: modafinil and methylphenidate improved a few test scores slightly, d-amphetamine did not, and the reviewers said users' belief in them is not supported by the evidence [3].
  • Smaller studies support L-theanine (200 mg sped choice reaction time [4]) and creatine (memory improved mainly in older adults [5]), while a review concluded caffeine helps attention and executive function [6].
  • Most cognition-supplement trials are small and flawed — 14 of 21 herbal trials in one review were at high risk of bias [7].

What the study did

The new study is a network meta-analysis, a review that pools trials of different products and ranks them even when the products were never tested head to head [1]. It combined 29 randomised trials with 2,107 healthy adults who took either Bacopa monnieri, Ginkgo biloba or a placebo, at doses of 300 mg a day or more of bacopa and 60 mg a day or more of ginkgo, and measured memory, attention and processing speed [1].

What it found

High-dose bacopa (600 mg a day or more) improved working-memory scores compared with placebo (standardised mean difference 2.03, 95% CI 1.28 to 2.78), and it also improved short-term memory [1]. The same dose outscored both ginkgo doses on working memory, and the lower bacopa dose (300 to under 600 mg a day) was the best option for delayed memory [1]. No option separated from the others on sustained attention, selective attention or processing speed [1]. The authors ranked high-dose bacopa first, but cautioned that no trial directly compared the two herbs, so the comparison is indirect [1].

How it fits

The result lands at the optimistic end of a mixed record. A 2014 meta-analysis of nine bacopa trials (518 people, mostly 12 weeks at 300 mg a day) found small gains in the speed of attention — choice reaction time about 11 milliseconds faster and a trail-making test about 18 milliseconds faster [8]. A 2025 randomised trial of 101 adults with self-reported memory and attention problems found that 300 mg a day for 12 weeks changed nothing on verbal learning, attention or working memory, though people reported less stress and fatigue after a demanding task [2]. Ginkgo looks weaker still: in the 2026 review it ranked below bacopa for memory [1], and a review of herbal supplements in older adults called its effects on thinking "consistently unclear" [7]. Two large randomised trials — 3,069 adults over a median of 6.1 years [9] and 2,854 adults over five years [10] — found that a standard ginkgo extract did not prevent dementia or Alzheimer's disease, and the first trial also found no slowing of decline in memory, attention, language or executive function [11]. Prescription "smart drugs" did little in pooled trials of healthy, well-rested adults: modafinil and methylphenidate produced small gains on some tests (standardised mean differences 0.12 and 0.21) and d-amphetamine produced none [3]. Everyday options look better: a systematic review of plant nootropics concluded caffeine improves attention and executive functions [6]; a single 200 mg dose of L-theanine sped choice reaction time (standardised mean difference 0.51), although its smaller stress effect was driven by high-risk-of-bias studies [4]; and creatine improved memory mainly in older adults, with no effect in younger people [5].

Limits

The new review's own comparison is indirect, because no trial has tested bacopa against ginkgo head to head [1]. Its effect sizes are much larger than those in earlier studies of the same herb [8], and in one review of 21 herbal cognition trials, 14 were at high risk of bias — a field-wide problem that makes big results hard to trust [7]. Supplements also vary in what they contain: ginkgo products have been found adulterated with colchicine, a prescription medicine [12].

The nuances

Safety: bacopa caused more digestive complaints and headaches than placebo in the 2025 trial [2]; ginkgo's side effects in trials mirrored placebo, and a meta-analysis of 18 trials found no clear bleeding risk from standard extracts [7] [13], though ginkgo is listed among supplements reported to interact with the blood thinner warfarin [14]. Reviewers describe heart, nerve and mental-health harms, dependence and legal problems with non-prescription "smart drugs" [15], which surveys show are common among students [16]. Bacopa's safety in pregnancy and breastfeeding is not established [17], and ginkgo is advised against in pregnancy and while breastfeeding [12]. Who this applies to: the trials tested specific standardised extracts, not whatever a label claims, in mostly healthy adults — and better scores on memory tests are not the same as being sharper at work or school [1].

Go deeper

  • Bacopa Monnieri — Bacopa is one of the most studied natural nootropics.
  • Ginkgo Biloba — Ginkgo is among the most studied natural nootropics, with the clearest signals on perceptual and motor tasks.

References

  1. Comparative effects of Bacopa monnieri and Ginkgo biloba on cognitive functions: A systematic review and network meta-analysis.. Phytomedicine, 2026.
  2. The Effects of a Bacopa monnieri Extract (Bacumen®) on Cognition, Stress, and Fatigue in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial.. Clin Drug Investig, 2025.
  3. How effective are pharmaceuticals for cognitive enhancement in healthy adults? A series of meta-analyses of cognitive performance during acute administration of modafinil, methylphenidate and D-amphetamine.. Eur Neuropsychopharmacol, 2020.
  4. Cognitive and affective effects of L-Theanine: a systematic review and meta-analysis of 31 randomized trials.. Mol Psychiatry, 2026.
  5. Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials.. Nutr Rev, 2023.
  6. Plant-derived nootropics and human cognition: A systematic review.. Crit Rev Food Sci Nutr, 2023.
  7. A systematic review of the safety and efficacy on cognitive function of herbal and nutritional medicines in older adults with and without subjective cognitive impairment.. Syst Rev, 2023.
  8. Meta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract.. J Ethnopharmacol, 2014.
  9. Ginkgo biloba for prevention of dementia: a randomized controlled trial.. JAMA, 2008.
  10. Long-term use of standardised Ginkgo biloba extract for the prevention of Alzheimer's disease (GuidAge): a randomised placebo-controlled trial.. Lancet Neurol, 2012.
  11. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial.. JAMA, 2009.
  12. Safety and efficacy of ginkgo (Ginkgo biloba) during pregnancy and lactation.. Can J Clin Pharmacol, 2006.
  13. Is there a risk of bleeding associated with standardized Ginkgo biloba extract therapy? A systematic review and meta-analysis.. Pharmacotherapy, 2011.
  14. Warfarin and food, herbal or dietary supplement interactions: A systematic review.. Br J Clin Pharmacol, 2021.
  15. Benefits and Harms of 'Smart Drugs' (Nootropics) in Healthy Individuals.. Drugs, 2022.
  16. Smart drugs and neuroenhancement: what do we know?. Front Biosci (Landmark Ed), 2021.
  17. Bacopa monnieri: Preclinical and Clinical Evidence of Neuroactive Effects, Safety of Use and the Search for Improved Bioavailability.. Nutrients, 2025.