Bacopa monnieri, also called brahmi, has more human research on memory and attention than on any other use, and the strongest of that research points to a measurable effect on some memory tests in healthy adults. Most of those trials ran for 12 weeks, and the research is still limited. The evidence for other uses, including Alzheimer’s disease, is weak.
Bacopa monnieri at a glance
Bacopa is a creeping herb that grows in wet lands and has a long place in Ayurvedic medicine. Its main active compounds are triterpenoid saponins called bacosides, and bacoside A is the most studied, according to a Bacopa chemistry review. A 2025 Nutrients review notes the herb has been used in Ayurveda for memory and for blood sugar control.
| Item | What the studies show |
|---|---|
| Forms studied | Standardized extracts, most often of the whole plant. One trial used a liquid essence, and some trials combined Bacopa with other ingredients. |
| Doses in studies | Healthy-adult trials used 300 mg to 600 mg or more a day, depending on the study; the 2012 review’s six trials used 300 to 450 mg of extract a day. Alzheimer’s trials used 125 to 500 mg twice daily. |
| Typical study length | Most trials ran 12 weeks. Across the reviews, trials ranged from 4 weeks to 12 months. |
| Main studied uses | Memory and attention in healthy adults; attention problems in children; mood and stress; Alzheimer’s disease (weakest evidence). |
What do the human studies show?
Memory in healthy adults: the strongest evidence
The strongest data come from meta-analyses, which pool several trials into one result. The newest is a 2026 network meta-analysis in Phytomedicine. It included 29 randomized controlled trials with 2,107 healthy adults. High-dose Bacopa, at 600 mg a day or more, improved working memory compared with placebo, with a standardized mean difference (SMD) of 2.03 (95% CI 1.28 to 2.78). SMD puts results measured on different scales onto a common scale, while the 95% CI shows the uncertainty around the estimate. The authors also report significantly greater benefits for short-term memory with Bacopa, and better delayed memory with low-dose Bacopa than with placebo.
An earlier 2014 meta-analysis pooled nine placebo-controlled trials with 518 people, all dosed for at least 12 weeks. It found faster scores on a timed attention test (Trail B, 17.9 ms shorter) and a 10.6 ms faster choice reaction time.
A 2012 systematic review of six trials in adults without dementia, each 12 weeks long and using 300 to 450 mg of extract a day, found improvement on 9 of 17 memory free-recall tests. It found little evidence of improvement in other areas of thinking.
A 2024 systematic review lists a 12-week placebo-controlled trial of 54 adults aged 65 and over. Their delayed word recall score improved compared with placebo.
Attention and reaction speed: the results conflict
The 2014 meta-analysis reports faster attention and reaction times. The 2026 network analysis found no significant difference in sustained attention, selective attention or processing speed. These two results point in different directions, so the speed question is still open.
Mood and stress: small and mixed
The 2024 systematic review lists a crossover trial of 17 healthy adults given 320 mg and 640 mg doses. It reported positive cognitive and mood effects and lower cortisol. The same review lists a separate crossover trial of 24 adults at the same doses that found no effect on ratings of stress and fatigue, or on cardiovascular activity. In the 12-week trial of 54 older adults, depression and anxiety scores fell in the Bacopa group.
In one 4-week trial of 42 adults with major depression who had not responded to citalopram, an antidepressant, adding Bacopa (300 mg) improved scores on the Hamilton depression rating scale. Bacopa was added to the antidepressant in that trial. It was not used in place of it.
Attention problems in children
The 2016 systematic review of child and teen trials included five studies. It found improvements in language, several memory areas, hyperactivity and attention-deficit domains, with small to medium effect sizes (average d of 0.42). Only 2.3% of participants reported mild side effects.
The 2024 systematic review also lists a 14-week placebo-controlled trial of 112 boys aged 6 to 14. Bacopa reduced errors and sped up reaction times, although overall behavior did not differ significantly between groups. A 6-month open-label trial of 31 children with ADHD reported lower symptom scores. Open-label means everyone knew they were taking the herb, and there was no placebo group.
Alzheimer’s disease and memory decline: the weakest evidence
A 2022 systematic review found five trials in people with Alzheimer’s disease or mild cognitive impairment, and judged all five to be at high risk of bias. It found no difference between Bacopa and placebo, or between Bacopa and donepezil, a prescription medicine for Alzheimer’s. The authors describe this as very low certainty evidence. No major safety issues were reported in the included trials.
The 2024 systematic review lists a one-year trial of 48 people with Alzheimer’s or mild cognitive impairment, comparing 300 mg of Bacopa with donepezil 10 mg. Memory-scale changes did not differ at 3, 6 and 9 months. At the final visit, one memory measure showed a significant difference. The same review lists a 90-day trial of 20 people with Parkinson’s disease that reported improved emotional function over time.
Which is better, Ginkgo biloba or Bacopa?
The 2026 network analysis is the only study here that compares the two herbs indirectly within the same analysis. High-dose Bacopa (600 mg a day or more) improved working memory more than high-dose ginkgo (240 mg a day or more), with an SMD of 1.94 (95% CI 1.10 to 2.77). Low-dose Bacopa did better than low-dose ginkgo on delayed memory. This is the closest answer to the question, and it is not a verdict. For the ginkgo side of the comparison, see ginkgo biloba benefits evidence. Section 7 explains how far this comparison can be pushed.
What doses did the studies use?
These are the amounts researchers tested. They are not advice on what to take.
| Study | Who took it | Dose used |
|---|---|---|
| 2012 systematic review | Adults without dementia | 300 to 450 mg of extract a day, 12 weeks |
| 2026 network meta-analysis | Healthy adults | Low: 300 to under 600 mg a day. High: 600 mg a day or more. |
| 2024 systematic review, Thai trial | 60 healthy adults | 300 mg or 600 mg once daily, 12 weeks |
| 2024 systematic review, child trial | 112 boys aged 6 to 14 | 160 mg a day (20 to 35 kg body weight) or 320 mg a day (over 35 kg), 14 weeks |
| 2024 systematic review, older adults | 54 adults aged 65 and over | 300 mg a day, 12 weeks |
| 2022 systematic review, Alzheimer’s trials | Five trials | 125 to 500 mg twice daily (range across trials) |
The 2012 review notes that three different Bacopa extracts were used across its six trials. A dose in one study therefore may not match the amount on a product label.
How long until Bacopa works?
Most trials measured results after several weeks of daily use, usually at the end of 12 weeks. That is the timeframe the research used. Acute trials looked at effects within hours of a dose; in the 17-person crossover trial, measurements were taken 1 and 2 hours after dosing. Plan around the full study length, not a faster result.
Side effects, safety and medicine interactions
Side effects reported in trials
| Side effect | Where it was reported (per the 2024 systematic review) |
|---|---|
| Nausea, stomach pain, diarrhea | 35 healthy adults aged 60 to 78, 3 months, open-label trial |
| Nausea, increased stool frequency, abdominal cramps | 98 healthy adults over 55, 12 weeks |
| Stomach upset | 54 adults aged 65 and over, 12 weeks |
| Dry mouth, increased appetite, headache, palpitations | 46 healthy adults aged 18 to 60, 12 weeks |
| Nausea, diarrhea, headache, dizziness, anxiety, insomnia | 48 people with Alzheimer’s or mild cognitive impairment, 1 year; no significant difference between groups |
| Sinusitis flare-up | 80 healthy adults aged 60 and over, 8 weeks, in a multi-ingredient mix containing Bacopa |
Most reported effects are mild stomach symptoms. The 2025 review says Bacopa is generally non-toxic, with no serious side effects reported.
Is it safe to take every day?
The 2025 review describes Bacopa as generally non-toxic, but calls for more research on optimal dosage and safety, especially in pregnant and breastfeeding women. The 2022 review reports no major safety issues in its included trials. The longest trial in the 2024 review ran for 12 months. Animal studies in a Bacopa chemistry review reported changes in thyroid hormone and anti-fertility effects in male mice. These are animal results, not human safety findings.
Is Bacopa hard on the liver?
Animal studies point toward liver protection. The 2024 review lists anti-hepatotoxic effects among the herb’s known functions, and an animal study described protection against morphine-related liver changes. No human study cited on this page measured liver safety. The side effects reported in trials were mostly stomach-related, but liver effects were not reported in these trials. If you have liver disease, ask your clinician before starting.
What not to mix with Bacopa?
The 2025 review says interactions with certain medications should be considered. Before you add Bacopa, show your full medicine list to your prescriber or pharmacist. In the trial that added Bacopa to citalopram, the study reported improved depression scores, which is what the study found and not a guide to combining them.
Who should talk to a clinician first?
The reviews name no outright ban. They do name these groups where caution or a clinician’s view should come first:
- People with an overactive thyroid. The 2025 review says contraindications in conditions like hyperthyroidism should be considered, and the animal thyroid findings are noted above.
- Pregnant and breastfeeding women. The 2025 review says more research is needed here.
- Anyone taking prescription medicines, because interactions are possible.
- Parents of children with ADHD. The child trials are few and small, and diagnosis and options belong with the child’s clinician.
- Anyone with liver disease.
- Anyone noticing memory changes. The Alzheimer’s data are very weak, so a clinician should assess the cause of memory changes.
What is still unknown?
Many trials are small and short, and several reviews flag design problems. The 2022 review rated all five Alzheimer’s trials as high risk of bias. The 2024 review lists small samples, lack of blinding and missing placebo comparisons as the main biases.
Results also conflict. The 2014 meta-analysis and the 2026 analysis disagree on attention speed. Two crossover stress trials at the same doses reached different conclusions.
The ginkgo comparison is indirect. The 2026 authors say the lack of direct comparisons may limit the strength of the evidence. The 2014 authors say only a large head-to-head trial against an existing medication will give definitive data on efficacy.
Long-term use is not well studied. A 2015 mechanisms and efficacy review calls for long-term chronic trials in older people to see whether the herb can prevent age-related cognitive decline. The 2016 child review calls for replicated study designs.
Absorption is another open question. In one trial reported in the 2024 review, Bacopa’s active compounds were detected in stool but not in plasma or urine. The 2025 review lists improving bioavailability as an active area of research.
How to read a label that lists Bacopa monnieri
| What to check | Why it matters |
|---|---|
| Amount in milligrams, and whether it is extract or whole herb | Healthy-adult trials used from 300 mg to 600 mg or more a day, depending on the study; the 2012 review’s six trials used 300 to 450 mg of extract a day. Compare the label’s per-serving amount with those studied amounts; they are not a recommendation. |
| Standardization | One trial’s extract was standardized to more than 55% combined bacosides A and B. Look for a bacoside percentage on the label. |
| Proprietary blends | Several trials tested Bacopa with other ingredients, such as L-theanine, vitamin B12 and Crocus sativus. In a blend, the Bacopa amount may not be listed, so ask the seller for it. |
| Form | Studies used standardized extracts, dry extracts and a liquid essence. Check whether your product matches the form that was studied. |
| Seller questions | Ask for the full ingredient list, the Bacopa amount and whether the product matches the amounts in a study. |
To learn how to separate research from marketing copy, see ingredient evidence vs marketing claims.
By ClinicalStudyConnect.com Research Desk
This article is for general information purposes only and does not constitute medical advice. Consult your doctor or qualified healthcare provider before making changes to your health routine.