Memory Supplements: What the Evidence Shows

7 April 2025, by SANUSq Research team
13 min reading time

Older man sitting on a sofa doing a jigsaw puzzle to keep his memory sharp

The memory shelf at the pharmacy is crowded, and the promises on it are generous. So what do memory supplements actually do? Large clinical trials have now tested several of the best-known ones, and the answers are not always the ones on the label. Here is an honest look at what a supplement can and can't do for an ageing brain.

Written by SANUSq Research Team | Medically reviewed by Dr Ajay Kumar, MD
Published: 7 April 2025 | Updated: 7 April 2025

Memory supplements: start with real shortfalls

The clearest role for any supplement is to fill a genuine gap. When a nutrient the brain relies on is running low, putting it back makes sense. When it isn't, adding more is a different proposition.

Three shortfalls come up regularly after 65:

Vitamin B12. Absorption falls with age, and long-term use of metformin or acid-reducing medicines (proton pump inhibitors) can lower it further. A marked deficiency can cause memory problems and confusion, which can improve when it is found and corrected in time.
Vitamin D. Very often low in winter, especially in people who spend little time outdoors.
Iron. Iron contributes to normal cognitive function, and a shortfall commonly brings tiredness and poor concentration.

In a review of vitamin B12 deficiency in older patients, Andrès et al. (2004) reported that it affects more than 20% of elderly people but often goes unrecognised because the signs are subtle, even though the consequences can be serious, particularly for the nervous system and the blood. The most frequent cause was not a poor diet but difficulty releasing B12 from food.

All of these can be checked with a simple blood test. That test, rather than the shop shelf, is the right place to begin.

Ginkgo biloba: the most instructive case

Ginkgo is among the best-selling supplements for memory in the world. It has also been through one of the most rigorous trials ever run on a supplement.

In the Ginkgo Evaluation of Memory study, DeKosky et al. (2008) randomised 3,069 people aged 75 and over, with normal cognition or mild cognitive impairment, to 120 mg of ginkgo extract twice a day or a placebo, and followed them for a median of about six years. Ginkgo did not reduce the rate of dementia or Alzheimer's disease, and side effects were similar in both groups.

The same trial also tracked how people's thinking changed year by year.

Snitz et al. (2009) analysed those yearly test scores and found that the rate of decline in memory, attention, language, visuospatial skills and executive function did not differ between the ginkgo and placebo groups.

A study of that size and length carries a lot of weight. It does not say ginkgo is harmful, and it was well tolerated. It says that, in older people, it did not change the course of memory and thinking over six years. That is useful to know when you are standing in front of the shelf.

Omega-3 and DHA: a promising idea, a modest result

DHA is a structural part of the membranes of brain cells, and DHA contributes to the maintenance of normal brain function, with the beneficial effect obtained from a daily intake of 250 mg. Observational studies also link regular fish eating with healthier cognitive ageing. It seemed reasonable to hope that capsules would do the same.

A Cochrane review by Sydenham et al. (2012) pooled randomised trials of omega-3 supplements in cognitively healthy people aged 60 and over, with cognitive data on 3,536 participants followed for up to 40 months. It found no benefit on cognitive function compared with placebo. Supplements were generally well tolerated, with mild digestive upset the most common side effect.

The lesson repeats across nutrients: what shows up in a lifetime of eating patterns doesn't necessarily reappear when you take a capsule for two or three years. Eating oily fish a couple of times a week remains a good habit. Expecting a measurable change in memory from a supplement is another matter.

B vitamins: needed, but more isn't better

B vitamins have authorised roles that are easy to overstate. Folate, B6 and B12 contribute to normal psychological function, and B12 also contributes to the normal function of the nervous system. That means an adequate intake is necessary. It does not mean that topping up someone who already has enough will sharpen their memory.

A systematic review and meta-analysis by Markun et al. (2021), covering 16 randomised trials and 6,276 participants without overt B12 deficiency or advanced neurological disease, found no evidence that B12 alone or a B complex improved any area of cognitive function.

This is the clearest illustration of the "real shortfalls" principle. Correcting a confirmed B12 deficiency matters. Taking B12 when your levels are already normal appears to do little for memory.

Multivitamins: a small, interesting signal

One of the more intriguing recent findings concerns the humble daily multivitamin. A multivitamin typically supplies several nutrients with authorised roles here: zinc and iodine, like iron, contribute to normal cognitive function.

Within the large COSMOS trial of adults aged 60 and over, Vyas et al. (2024) combined three cognitive substudies and found that people taking a daily multivitamin-mineral had slightly more favourable changes in global cognition and episodic memory scores over two to three years than those on placebo. The differences were small, and the authors estimated them as roughly equivalent to two years of cognitive ageing.

These are research findings in a mostly well-nourished American population, measured on test scores, and they need confirming elsewhere. They are not a reason to expect a noticeable change in everyday memory, but they do suggest that broad, modest nutritional cover may matter more than any single "brain" ingredient.

Focus and nootropic blends: what's inside

Products sold for concentration often combine caffeine, taurine, B vitamins and sometimes ginseng or bacopa. A few points are worth knowing.

Caffeine genuinely increases alertness in the short term, but a cup of coffee does the same job. Its effect fades with regular use, and it can disturb sleep, which is the biggest single driver of next-day attention.
B vitamins contribute to normal energy-yielding metabolism, which again means adequate intake is needed, not that extra improves performance.
Herbal "nootropics" have limited data, mostly from short, small studies.

A meta-analysis of nine randomised trials (518 participants) by Kongkeaw et al. (2014) found that standardised bacopa extract taken for at least 12 weeks was associated with small improvements on tests of attention speed and reaction time. The authors concluded that larger, well-designed trials are needed before firm conclusions can be drawn.

Which supplements for memory in older age?

To put it plainly: in a well-nourished older person with no deficiency, no supplement has been shown to prevent dementia or reliably improve memory. In someone who is deficient, correcting the shortfall is worthwhile, sometimes clearly so.

In between lies a grey zone: a poor or restricted diet, a small appetite, living alone, or a long list of medicines. That is exactly where a doctor's or pharmacist's view is worth more than a product choice, because the real question isn't "which supplement?" but "which shortfall?"

What works, and gets overlooked

The approaches with the strongest evidence don't come in a bottle. Regular physical activity is at the top of the list for thinking skills in later life. Sleep follows closely, since memories are consolidated overnight. After that come keeping blood pressure and blood sugar in check, treating hearing loss (an often-ignored factor), staying mentally engaged and keeping up social contact.

In the FINGER trial, Ngandu et al. (2015) randomised 1,260 at-risk adults aged 60–77 to a two-year programme combining diet guidance, exercise, brain training and monitoring of vascular risk factors, or to general health advice. The programme group showed a small but significant advantage on a broad battery of cognitive tests.

None of these levers is for sale, which may be part of why they get less attention than the products on the shelf.

Safety: supplements aren't neutral

Ginkgo may increase the risk of bleeding, particularly with blood thinners such as warfarin or antiplatelet medicines like aspirin or clopidogrel. It is usually stopped before surgery; ask your surgical team.
High-dose vitamin B6 taken for long periods has been linked to nerve damage, felt as tingling or numbness in the hands and feet.
St John's wort, found in some "balance" or mood formulas, interacts with many medicines, including antidepressants, the contraceptive pill and blood thinners.

A systematic review by Tan and Lee (2021) identified 78 foods, herbs and supplements reported to interact with warfarin and listed ginkgo biloba and St John's wort among those linked to an increased risk of bleeding. The authors advised patients to check with a healthcare professional before starting any new supplement.

Hadtstein and Vrolijk (2021) reviewed the growing number of reports linking pyridoxine (vitamin B6) supplements to sensory peripheral neuropathy and explored how excess intake injures sensory nerves.

Above all, memory problems that are new or getting worse are not something to self-treat. See your doctor. Several causes, from B12 deficiency and thyroid problems to medication side effects, low mood and poor sleep, can be identified and addressed.

The bottom line

If you are looking for the best supplements for memory, the most useful first step is a check-up: look for deficiencies, and review hearing, blood pressure, sleep and medicines. Then invest in what has the best evidence: moving, sleeping, staying socially and mentally active, and eating well. Treat supplements as what they are: useful for filling a shortfall, with little established effect when there isn't one.

Frequently asked questions

Do memory supplements work?

In well-nourished people without a deficiency, large trials of ginkgo, omega-3 and B vitamins have not shown a meaningful effect on memory. Correcting a confirmed shortfall, such as low vitamin B12 or iron, is worthwhile and is best decided after a blood test.

Does ginkgo biloba improve memory?

A trial of more than 3,000 people aged 75 and over, followed for about six years, found no reduction in dementia and no difference in the rate of memory decline compared with placebo. It was well tolerated, but it can increase bleeding risk with blood thinners.

Is omega-3 good for memory?

DHA contributes to the maintenance of normal brain function at 250 mg a day. However, a Cochrane review of trials in healthy older adults found no benefit of omega-3 supplements on cognitive function. Oily fish remains a good part of a balanced diet.

What is the best supplement for focus and concentration?

Caffeine boosts short-term alertness but can disrupt sleep, the biggest factor in next-day focus. B vitamins, iron, zinc and iodine are needed in adequate amounts, but extra doesn't appear to enhance performance in someone who already has enough.

When should I see a doctor about memory problems?

Whenever forgetfulness is new, getting worse, worrying you or the people close to you, or affecting daily life. Several causes, including vitamin deficiencies, thyroid problems and medication side effects, can be identified and addressed.

Are memory supplements safe?

Not always. Ginkgo can raise bleeding risk with anticoagulants, long-term high-dose vitamin B6 has been linked to nerve damage, and St John's wort interacts with many medicines. Check with your doctor or pharmacist if you take any regular medication.

References

Andrès E, Loukili NH, Noel E, et al. Vitamin B12 (cobalamin) deficiency in elderly patients. CMAJ. 2004;171(3):251–259. PMID 15289425
DeKosky ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. 2008;300(19):2253–2262. PMID 19017911
Snitz BE, O'Meara ES, Carlson MC, et al. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial. JAMA. 2009;302(24):2663–2670. PMID 20040554
Sydenham E, Dangour AD, Lim WS. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database of Systematic Reviews. 2012;2012(6):CD005379. PMID 22696350
Markun S, Gravestock I, Jäger L, et al. Effects of vitamin B12 supplementation on cognitive function, depressive symptoms, and fatigue: a systematic review, meta-analysis, and meta-regression. Nutrients. 2021;13(3):923. PMID 33809274
Vyas CM, Manson JE, Sesso HD, et al. Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS. American Journal of Clinical Nutrition. 2024;119(3):692–701. PMID 38244989
Kongkeaw C, Dilokthornsakul P, Thanarangsarit P, Limpeanchob N, Norman Scholfield C. Meta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract. Journal of Ethnopharmacology. 2014;151(1):528–535. PMID 24252493
Ngandu T, Lehtisalo J, Solomon A, et al. A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. Lancet. 2015;385(9984):2255–2263. PMID 25771249
Tan CSS, Lee SWH. Warfarin and food, herbal or dietary supplement interactions: a systematic review. British Journal of Clinical Pharmacology. 2021;87(2):352–374. PMID 32478963
Hadtstein F, Vrolijk M. Vitamin B-6-induced neuropathy: exploring the mechanisms of pyridoxine toxicity. Advances in Nutrition. 2021;12(5):1911–1929. PMID 33912895

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The health information in this article is provided for educational purposes only. Consult your healthcare professional before making any medical decisions.

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