Brain and memory
What the NHS, Alzheimer's Research UK and the Royal College of Psychiatrists say about ginkgo, omega-3, B vitamins and other supplements sold for memory.
The NHS lists lifestyle changes as the ways to lower the risk of dementia, and names no supplement. Alzheimer's Research UK finds no conclusive evidence for ginkgo and not enough for B vitamins, and says research on omega-3 supplements is still going on. Below is what these and other sources say about the supplements sold for memory, and the safety points they raise.
NHS: Lists a balanced diet, a healthy weight, regular exercise, alcohol within limits, not smoking and healthy blood pressure as ways to lower the risk of dementia.
Each line below is a short summary of what the named source says, with a link to read it in full. None of it is medical advice.
Limited evidence
Multivitamins
One tablet or capsule combining several vitamins and minerals.
- Harvard Health: Some evidence on memory in people aged 60 and over, from one trial.
- NCCIH: No clear effect on thinking skills in well-nourished people.
Lion's mane
A large white edible mushroom, sold dried and as powders, capsules, liquids and gummies.
- Cleveland Clinic: Research is limited; more studies are needed.
- Cleveland Clinic: No real guidelines on how much to take; avoid if allergic to mushrooms.
No good evidence
Ginkgo
An extract of the leaves of the ginkgo tree, which originated in China.
- Alzheimer's Research UK: No conclusive evidence for ginkgo in dementia; research results so far have been mixed.
- NCCIH: Did not lower dementia risk in three large studies; effect in healthy people uncertain.
Also covered by RCPsych, NCCIH, Cleveland Clinic and Harvard Health.
Omega-3
Fats found in oily fish, and in some plant oils, nuts and seeds; supplements come from fish, krill or algae.
- Alzheimer's Research UK: Research is ongoing into whether omega-3 supplements affect dementia risk.
- Harvard Health: Eating fish is linked to less cognitive decline; fish oil supplements have not shown this.
Also covered by NCCIH and Cleveland Clinic.
B vitamins
A group of eight vitamins, including B6, B12 and folate, found in many foods.
- Alzheimer's Research UK: Not enough evidence that B vitamin supplements stop or slow dementia.
- Alzheimer's Research UK: Folic acid and B12 do not affect memory and thinking without a B12 deficiency.
Also covered by NCCIH and Cleveland Clinic.
Vitamin E
A group of compounds found in plant oils, nuts and seeds, and wheatgerm.
- RCPsych: No good evidence it makes a difference to memory or slows dementia.
- NIH ODS: Little evidence for it on brain health, in healthy people or with mild problems.
Also covered by NCCIH and Cleveland Clinic.
Vitamin D
A vitamin the body makes when skin is in sunlight. Oily fish, eggs and fortified foods have some; supplements come as D3 or D2.
- Alzheimer's Research UK: Supplement studies have not shown a clear effect on dementia risk.
- Alzheimer's Research UK: NHS advice to consider it in autumn and winter is not about dementia.
Also covered by Cleveland Clinic.
Things to check
- Alzheimer's Research UK: Speak to your doctor before starting supplements; they can cause side effects and interfere with prescribed medicines.
- NHS: A lack of vitamin B12 or folate can cause memory problems; see a GP, who may arrange a blood test.
- NCCIH: Ginkgo may raise the risk of bleeding in people taking anticoagulants such as warfarin; check with a doctor if you take any medicine.
- Cleveland Clinic: High doses of vitamin E supplements are linked to a higher risk of bleeding in the brain, which can be life-threatening.
- NHS: Taking 540mg (800 IU) or less a day of vitamin E supplements is unlikely to cause any harm.
If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.
Sources
- Can dementia be prevented?Risk factors for dementia and the lifestyle changes that lower the risk.
- Diet and dementia risk explainedDiet and dementia risk, with questions on ginkgo, B vitamin, vitamin D and omega-3 supplements.
- Complementary and alternative medicines: herbal remediesHerbal remedies and supplements used for mental health, sleep and memory, with side effects and interactions.
- Ginkgo: Usefulness and SafetyWhat is known about ginkgo's usefulness and safety, including large studies on dementia.
- Dietary Supplements and Cognitive Function, Dementia, and Alzheimer's Disease: What the Science SaysA summary for health professionals of the research on supplements for memory, thinking and dementia.
- Vitamin E: Fact Sheet for ConsumersHow much vitamin E people need, where it comes from, the research on health, and safety.
- Do Brain Health Supplements Really Work?The research on omega-3, B vitamins, vitamin E, vitamin D, lion's mane and ginkgo for the brain.
- Health Benefits of Lion's Mane MushroomsWhat lion's mane is, where the research on it stands, and what to consider first.
- Don't buy into brain health supplementsThe evidence on supplements sold for memory, including omega-3, ginkgo and multivitamins.
- Vitamin EWhere vitamin E comes from, how much adults need, and how much is safe to take.
- Vitamin B12 or folate deficiency anaemiaSymptoms and causes of low vitamin B12 or folate, and seeing a GP for a blood test.
Sources checked 28 September 2026. Prices checked 20 October 2026, ranked purely by price per dose. Which sources these pages use.