~/blog/does-bacopa-make-you-tired-what-trials-recorded
Does bacopa make you tired? What six trials recorded
Not in the trial abstracts we read. They record gut upset and headaches; the 2025 trial that measured fatigue over weeks reported less of it, not more.
Not according to the trial record this desk read. None of six bacopa trial abstracts lists tiredness or drowsiness as an adverse event; the side effects they name are digestive, plus headaches in one. A 2025 trial that measured fatigue reported less of it after a demanding task, and a 2013 single-dose study found no effect on task-induced fatigue.
That answer to “does bacopa make you tired” is evergreen: it rests on studies published between 2001 and 2025, not on anything that changes week to week. The newest of them, a 12-week trial of the Bacumen extract, is the only one in the set to treat fatigue as a measured outcome over weeks rather than hours. This desk read all six abstracts through NCBI’s E-utilities on 4 October 2026, and ran a PubMed search the same day for bacopa trials that mention fatigue, drowsiness, somnolence, sedation, tiredness or sleepiness.
It follows our earlier posts on the bacopa trial record: stomach upset, how long it takes to work and whether it needs cycling. Same method: the abstract says what it says, and where it says nothing, so do we.
Where does the “bacopa makes you sleepy” idea come from?
Partly from tradition. The introduction to a 2008 trial paper describes bacopa as used for centuries in Ayurvedic medicine as a memory and learning enhancer, sedative and anti-epileptic. That is a description of historical use, not a finding about what a 300 mg capsule does to a modern adult, and it should not be read as one.
Partly from brand advice. Mind Lab Pro’s timing guide, which ranks near the top for this query, tells readers that if bacopa makes them feel relaxed or sleepy, switching to an evening dose is a practical fix. It may well be good practical advice. In the passage this desk read, though, it names no trial behind the idea that sleepiness is something bacopa does.
And partly from people’s own reports online. A first-person account is a real experience, and a trial average cannot rule any one of them out. What they cannot do is tell you how often it happens, or whether it happens more than on a placebo.
Does bacopa make you tired in clinical trials?
Every cell below comes from the abstract, not the full paper. Where the lines we read did not carry a figure, the cell says so rather than filling it in.
| Study (PMID) | Extract, daily dose | Length | Participants | Fatigue measured? | What the abstract records |
|---|---|---|---|---|---|
| Lopresti and Smith 2025 (41091332) | Bacumen, 300 mg | 12 weeks | 101 randomised, 87 completed | Yes, secondary outcome | Greater fall in fatigue after a demanding task; more adverse reactions on bacopa (p = 0.024), mainly digestive and headaches |
| Phytotherapy Research 2013 (23281132) | KeenMind CDRI 08, 320 mg and 640 mg single doses | Acute, crossover | 24 | Yes, task-induced ratings | No effect on task-induced stress or fatigue |
| Calabrese 2008 (18611150) | Standardised extract, 300 mg | 12 weeks | 54 randomised, 48 completed | Not named | 9 adverse events on bacopa, 10 on placebo, mainly stomach upset |
| Morgan and Stevens 2010 (20590480) | BacoMind, 300 mg | 12 weeks | 98 commenced, 81 completed | Not named | Increased stool frequency, cramps and nausea vs placebo |
| Stough 2001 (11498727) | 300 mg | 12 weeks | Not in lines read | Not named | No adverse-event line |
| Neuropsychopharmacology 2002 (12093601) | Not in lines read | 3 months, retested 6 weeks after | Not in lines read | Not named | No adverse-event line |
“Not named” means the abstract does not name fatigue among its outcomes. “No adverse-event line” means the abstract does not report side effects at all, which is a statement about the summary, not a finding that the trial saw none.
What did the Bacumen trial find about fatigue?
The 2025 Bacumen trial, published in Clinical Drug Investigation (online 15 October 2025, in the December 2025 issue), gave 101 adults aged 40 to 70 with self-reported memory and attention problems either 300 mg of Bacumen a day (50 people) or a placebo (51) for 12 weeks. Of those, 87 finished: 47 on placebo, 40 on bacopa.
On its primary measures, verbal learning, attention and working memory, the abstract reports no difference between the groups. On secondary measures it reports greater reductions with bacopa in self-reported stress reactivity, and in fatigue and stress after a cognitively demanding computer task.
Three things keep that from becoming a promise. Fatigue was a secondary outcome, not the question the trial was built to answer. The authors themselves say the anti-fatigue effects require investigation in future trials. And the abstract carries a competing-interests declaration, which this desk has not assessed in full. What the trial does tell a reader asking “will this make me tired” is narrower and more useful: in the one longer trial that asked, the bacopa group did not report more fatigue.
It also reported more side effects. Adverse reactions were more frequent on bacopa (p = 0.024), mainly digestive complaints and headaches, with no serious ones. Tiredness is not in that list.
What did the acute CDRI 08 study show?
The 2013 crossover study in Phytotherapy Research gave 24 healthy volunteers single doses of 320 mg and 640 mg of KeenMind CDRI 08, and a placebo, then ran them through six rounds of a demanding test battery. The 320 mg dose improved performance on some rounds. The abstract says the treatments had no effect in attenuating task-induced ratings of stress and fatigue.
That is a same-day result from a small group, so it says little about weeks of use. It is still the second trial in the set to rate fatigue directly, and neither one points towards bacopa causing it.
What about the trials that only recorded side effects?
Calabrese 2008 and Morgan and Stevens 2010 are both 12-week, placebo-controlled trials at 300 mg a day, and both abstracts name their side effects. Calabrese records nine adverse events on bacopa and ten on placebo, mainly stomach upset. Morgan and Stevens, testing Natural Remedies’ BacoMind, says bacopa caused increased stool frequency, abdominal cramps and nausea. Neither names tiredness.
The full Calabrese paper counts 41 adverse events, 23 on placebo and 18 on bacopa. This desk did not read its itemised list, so we make no claim either way about whether fatigue appears in it.
How wide was the search?
The PubMed search this desk ran on 4 October 2026, restricted to randomised and clinical trials, returned four records. Two are rows in the table above. The other two are not bacopa-alone studies: one tested a B-vitamin and herbal combination, the other a multi-herb Ayurvedic formula. So in that search, the controlled evidence that speaks directly to bacopa and fatigue is thin, two trials deep, and both are in the table.
Does bacopa make you sleepy?
The trial abstracts we read do not say so. None of the six lists sleepiness, drowsiness or tiredness as an adverse event, and the two that measured fatigue found either less of it or no effect on it. Abstracts summarise, and a single person’s response is not a trial average, so if you feel drowsy on bacopa that is real information about you, whatever the tables say.
What are the most common side effects of bacopa?
In the abstracts we read, digestive ones: stomach upset, nausea, abdominal cramps and increased stool frequency. The 2025 Bacumen trial adds headaches. WebMD’s line on common side effects names loose stools or diarrhoea, gas, nausea and upset stomach. Our post on bacopa and stomach upset sets the gut evidence out trial by trial.
When is the best time to take bacopa?
No abstract we read tested morning against evening dosing, and none says when participants took their capsules. Mind Lab Pro advises an evening dose if bacopa makes you relaxed or sleepy; in the passage we read, it names no trial behind that. Following the label on your product, and keeping the time consistent, is the guidance the evidence supports.
Should I take bacopa at night if it makes me tired?
Moving the dose is a reasonable thing to try, and it is what brand guides suggest, but no trial we read compared timings, so it is practical advice rather than tested advice. If tiredness persists, or arrives with anything else unexpected, stop and ask a pharmacist or doctor, especially if you take other medicines.
Where this leaves the label-reader
Most trials in the table used a named or standardised extract at a stated dose: Bacumen, BacoMind, KeenMind CDRI 08, or a standardised 300 mg. Those names are trade names, not proof of anything, but they are the only way to match a product to a row. A blend that hides its bacopa figure gives you nothing to compare. None of this is medical advice. Bacopa is an ingredient in adult supplements not intended to diagnose, treat, cure or prevent any disease; if it leaves you tired, that is worth a conversation with a clinician, not a forum.