Brain supplements and supplements for memory: what's studied and what isn't

How this section works

No “brain upgrade” promises here. For each supplement we say what human studies showed, at what dose and who it doesn’t suit, and when the evidence is thin, we tell you. Links to iHerb open a selection of the right form, so you can compare brands yourself.

Find your option: brain and memory

Pick what bothers you to see where to start and what not to expect

What bothers you?

Can't concentrate My memory is worse I rarely eat fish Vegan, metformin, 50+ Thinking of ginkgo Lion's mane, nootropics

Where to start

Sleep first, then sensible caffeine

Ordinary caffeine is the best-studied focus aid. EFSA says single doses up to 200 mg and up to 400 mg a day are safe for healthy adults. L-theanine is often paired with caffeine, but the studies are small.

Rule of thumb: a 200 ml mug of filter coffee has about 90 mg of caffeine

EFSA advises no more than 200 mg of caffeine a day from all sources in pregnancy.

L-theanine and caffeine

Brain supplements: what really affects memory

Focus and memory usually suffer for reasons that can be fixed:

• poor sleep and long-term stress;
• low B12 or folate, which can also cause tiredness and pins and needles;
• thyroid problems, diabetes, or liver and kidney problems;
• depression and side effects of medicines.

Your GP finds these with blood tests and an examination, not with trial and error at the supplement shelf. Our tests and deficiencies section explains what to ask about. Vegans need vitamin B12 from a supplement or fortified foods. People over 50 and anyone on metformin or acid-reducing tablets should ask about a B12 test.

According to an NCCIH review, no supplement has yet been shown to prevent dementia. Short courses of B vitamins didn’t improve thinking in older adults, though longer use may slightly slow decline. For vitamin E and curcumin, the evidence is too thin to draw conclusions.

Supplements for memory: topics in this section

Topic	What’s known	Guide
Omega-3	the best data are for eating fish; capsules didn’t help in Alzheimer’s	how to choose fish oil
Vitamin B12	matters if you’re low; otherwise no need	vitamin B12
Ginkgo biloba	didn’t lower dementia risk; raises bleeding risk with blood thinners	ginkgo biloba side effects
Lion’s mane	little research in people	lion’s mane
NAD and NMN	little research in people	NMN supplements
Lecithin and phosphatidylserine	little evidence	lecithin
L-theanine and caffeine	caffeine is better studied; L-theanine has small trials	L-theanine and caffeine
Creatine	well studied for strength; little data on memory	creatine

Not sure you need any of these? Take our vitamin check: it shows what official advice says for your diet and lifestyle.

Nootropics in the UK: what to check

• Blends without doses. If the label lists a “proprietary blend” with no amount for each ingredient, you don’t know what you’re taking.
• Hidden caffeine. Add up all your caffeine: coffee, tea, energy drinks and capsules. EFSA says up to 400 mg a day, and up to 200 mg at a time, is safe for healthy adults.
• Vitamin B6 in brain formulas. Too much can damage nerves. Check the dose with our B6 checker.
• Prescription “smart drugs”. Some products sold for focus are medicines. Don’t buy them without a prescription.

Who should take care

• In pregnancy, ginkgo may be unsafe, and EFSA advises no more than 200 mg of caffeine a day.
• On blood thinners, take ginkgo or high-dose omega-3 only if your GP or anticoagulation clinic agrees.
• If you take regular medicines, ask your pharmacist about herbal brain products and check our vitamin compatibility chart.
• If your memory is getting worse quickly, see your GP rather than starting a supplement.

Before you buy, run through this short list:

Before you buy a "memory" supplement

Tick what's true for you. Ticks are saved in this browser only

0 / 7 ticked

• I sleep enough and I'm not under constant stress. Poor sleep and long-term stress top the list of fixable reasons for poor focus.
• I've ruled out low B12. Vegans need a supplement. If you're over 50 or take metformin or acid-reducing tablets, ask your GP about a test. Read more
• My memory hasn't clearly got worse over the past few months. If it has, see your GP first. They'll usually check B12 and folate, thyroid function, blood sugar, and liver and kidney function.
• The label gives a dose for every ingredient. A "proprietary blend" with no amounts means you don't know what you're taking.
• I've added up all my caffeine for the day. EFSA says up to 400 mg a day, and up to 200 mg at a time, is safe for healthy adults. In pregnancy, no more than 200 mg a day.
• I've checked the B6 in my brain formula. Too much can damage nerves. Read more
• I don't take blood thinners, or my GP has agreed. Ginkgo and high-dose omega-3 need your GP's or anticoagulation clinic's go-ahead. Read more

Omega-3 on iHerb

How to choose on iHerb

1. Rule out low B12 and sleep problems first.
2. Choose one ingredient with a clear dose rather than a ten-ingredient blend.
3. Add up caffeine and vitamin B6 from every source.
4. Judge the effect honestly: after a few weeks, without starting anything else new.

Bottom line: what to choose

Little fish in your diet

Omega-3: 250–500 mg EPA+DHA

If you eat oily fish less than once a week

Omega-3 on iHerb

Vegan diet

Vitamin B12

Without it, a deficiency develops over time

B12 on iHerb

Coffee for focus

L-theanine 200 mg

Often paired with coffee; modest evidence

L-theanine on iHerb

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FAQ

Which vitamins actually help the brain and memory?

The ones you’re short of. Low B12 and folate can cause memory problems, and a blood test shows whether you have them. In older adults, short courses of B vitamins didn’t improve thinking skills. If you eat little fish, omega-3 makes sense.

Do nootropics work? Are they legal in the UK?

There’s no convincing evidence that supplements improve memory or prevent dementia. That’s NCCIH’s conclusion for ginkgo, omega-3, B vitamins, vitamin E and curcumin. Some products sold online as nootropics or ‘smart drugs’ are prescription medicines, not supplements, so don’t buy them without a prescription.

Does ginkgo biloba help memory?

In the large GEM study, over 3,000 people aged 75 and over took ginkgo for about 6 years. Dementia was just as common as with a placebo. Ginkgo can also raise bleeding risk with blood thinners.

Is omega-3 good for the brain?

The most consistent findings come from eating fish, not from capsules. Omega-3 supplements didn’t help people with Alzheimer’s disease. Capsules make sense if you rarely eat oily fish.

When should I see my GP about memory?

If your memory or concentration has clearly got worse, especially over a few months. Your GP will usually check B12 and folate, thyroid function, blood sugar, and liver and kidney function. Don’t delay while you try supplements.

Sources

1. NCCIH. 7 Things To Know About Dietary Supplements for Cognitive Function, Dementia, and Alzheimer's Disease
2. NCCIH. Dietary Supplements and Cognitive Function, Dementia, and Alzheimer's Disease: What the Science Says
3. NCCIH. Ginkgo: Usefulness and Safety
4. NHS. Tests for diagnosing dementia
5. NHS. Vitamin B12 or folate deficiency anaemia – Symptoms
6. EFSA. Caffeine