What is Bacopa monnieri? A plain-English guide

Bacopa monnieri is a plant that is also called Brahmi or Waterhyssop [8].

Studies tested extracts, which are concentrated forms of the plant [1].

Ayurveda uses bacopa for memory [8]. A few small studies tested whether one dose does anything within 2 hours [6][7].

Does bacopa help with memory?

Evidence grade for delayed recall: B, moderate. Why this grade

A systematic review is a study that gathers all the trials on one question and sums them up. One such review looked at six randomized controlled trials [1]. In this kind of trial, people are split by chance into groups, and one group gets a placebo, a dummy pill.

All six lasted 12 weeks and studied adults without serious memory or thinking problems [1]. Compared with a placebo, bacopa improved 9 of 17 tests of free recall, which means remembering a list without hints [1]. There was little sign of benefit in other areas of thinking [1].

A larger 2026 review pooled 29 trials of bacopa or another herb, ginkgo, with 2,107 healthy adults [2]. It was a network meta-analysis, which compares treatments both directly and across different trials. For delayed memory, low doses of bacopa did better than a placebo [2]. The authors say the lack of direct comparisons may limit the strength of this evidence [2].

Single trials point both ways. In 98 healthy adults over 55, a branded extract called BacoMind improved learning and delayed recall on a word-list test, compared with a placebo [3]. Of the 98, 81 finished [3]. But in 72 healthy adults aged 35 to 60, there was no clear difference on any thinking test, in a trial supported by Hindustan Unilever [4]. Three of its authors worked for Unilever, and a Unilever company sells products that contain Brahmi [4].

A third trial, funded by US Pharma Lab, studied 101 adults aged 40 to 70 with self-reported memory and attention problems [5]. Its lead author runs a research company that has received funding from supplement companies [5]. Among the 87 people who finished, it found no difference on any of its main tests: word-list learning, attention and working memory [5].

In all three of these trials, neither the volunteers nor the researchers knew who got bacopa [3][4][5]. So evidence is mixed. The trials lasted about 12 weeks, so they do not show what happens with longer use [1].

Does one dose of bacopa do anything?

Evidence grade for acute cognitive performance: C, limited. Why this grade

The single-dose studies are small, and their results disagree [6][7]. In 38 healthy adults, 300 mg of bacopa made no clear difference on any test 2 hours later, compared with a placebo [6]. In a study of 17 healthy adults, each person took every treatment in turn [7]. Doses of 320 mg and 640 mg improved scores on two tasks 1 and 2 hours later [7].

Both studies came from researchers at the same university [6][7]. The authors of the second study say the results need to be repeated in a larger group [7].

Does bacopa help with stress?

Evidence grade for perceived stress: C, limited. Why this grade

Evidence is mixed. Two 12-week trials, funded by US Pharma Lab and Hindustan Unilever, used questionnaires where people rate their own feelings [4][5]. In the US Pharma Lab trial, people taking bacopa reported larger drops in how strongly they react to stress [5]. This was not the trial's main question, and it counted only the 87 of 101 people who finished [5].

In the Hindustan Unilever trial, there was only a trend toward lower anxiety in the moment [4].

To see what each grade means, read how we grade evidence.

Table: Doses used in studies (not a recommendation)

A 2025 review describes doses in studies as usually 300 to 600 mg a day [8]. The same review says more research is needed to work out doses and make sure of safety [8]. These are amounts used in research, not a recommendation for anyone.

A 2025 review says stomach and gut problems are the most common side effects [8]. In a 12-week trial of BacoMind in healthy adults over 55, bacopa caused more frequent stools, stomach cramps and nausea than a placebo [3]. In the trial funded by US Pharma Lab, people on bacopa reported more side effects than people on a placebo [5]. These were mostly stomach complaints and headaches [5].

A 2023 letter reports a case of necrotizing myopathy, a serious muscle condition, after use of a bacopa supplement [10]. We could not read the letter, so its details are not verified as of November 12, 2026.

In lab tests, bacopa extract reduced the activity of four enzymes: CYP1A2, CYP3A4, CYP2C9 and CYP2C19 [9]. They belong to the cytochrome P450 family, which the body uses to break down many medicines. The authors say this could contribute to herb-drug interactions [9].

The 2025 review also reports an interaction with amitriptyline [8]. It reports back pain and heavy sweating with the antidepressant agomelatine [8]. It also reports a heart attack with the antidepressant moclobemide [8]. The review gives no study details, so these reports do not show that bacopa caused the events. It also advises care with medicines that affect thyroid hormone levels [8].

If you take any of these medicines, talk to your doctor or pharmacist before combining them with bacopa.

• Pregnant and breastfeeding women. A 2025 review notes a lack of research on safe use in this group [8].
• People with an overactive thyroid. The same review advises special caution, based on a study in male mice [8].
• People who take medicines broken down by the CYP enzymes above, given the lab findings [9].

Anyone in these groups should talk with a clinician about bacopa.