Supplements and memory claims

Store shelves and TV ads are full of pills that promise a sharper memory. When someone you love is forgetting things, it is natural to want to try them. Most need no prescription.

This page covers what research says about popular products, which ones carry real risks, and how to spot a scam. The short version: no food, vitamin or supplement has been proven to prevent, treat or cure Alzheimer's disease.³

How supplements are sold in the U.S.

Prescription medicines must prove they are safe and work before the FDA approves them. Supplements do not. The maker does not have to show the FDA its evidence before selling a product.³ The FDA also does not check each batch. Companies are expected to police their own quality, so the label may not match what is inside.³

There is one firm rule. A product that claims to treat, prevent or cure a disease like Alzheimer's is legally a drug. If it has not been approved as a drug, selling it with those claims is against the law.⁹

That rule is broken often. The FDA has sent many warning letters to companies selling pills, tablets and oils with Alzheimer's claims. In one action, it sent 17 letters about more than 58 products. Many were sold as supplements on websites and social media.⁹

What the research shows, product by product

Sources for the table: NCCIH, NIA, FTC and published studies.^1,2,4,6,7

Ginkgo biloba

Ginkgo comes from the leaves of the ginkgo tree. The largest study was the Ginkgo Evaluation of Memory (GEM) study, paid for by the National Institutes of Health. More than 3,000 people aged 75 and older took ginkgo or a placebo (a look-alike pill with no active ingredient) for about 6 years. Dementia, including Alzheimer's, was just as common in both groups.² It also did not slow the decline in thinking that comes with age.¹

Some smaller studies of people who already have dementia suggest a slight benefit on thinking tests. But results are mixed, and the studies did not show better daily functioning.^1,2 Limited research

Safety: Ginkgo may raise the risk of bleeding, especially with blood thinners such as warfarin. It can also cause headache, dizziness and an upset stomach.^1,2

Omega-3 fatty acids (fish oil and DHA)

Omega-3s are fats found in fish such as salmon and sardines. Some research has linked omega-3s to a lower risk of dementia.³ But taking them as pills has not held up in trials.

• In a large U.S. trial of DHA (one type of omega-3) in people with Alzheimer's, there was no overall benefit.³
• A Cochrane review (a careful summary of all good trials) of people with mild to moderate Alzheimer's found no convincing benefit.¹
• A review of 38 trials with almost 50,000 people found that omega-3 pills probably have little or no effect on new memory or thinking problems.¹

Side effects are usually mild, such as stomach upset.¹ Experts say there is not enough evidence to recommend omega-3 pills to prevent or treat Alzheimer's.³

B vitamins: B6, B12 and folic acid

When B12 matters. A true lack of vitamin B12 can cause memory problems, confusion and even dementia-like symptoms.⁸ Older adults are at higher risk because many absorb less B12 from food. Some common medicines also lower B12, including metformin for diabetes and stomach acid reducers such as omeprazole.⁸

A simple blood test can check your level. If it is low, treatment can help. This is one reason a full medical checkup comes first. See treatable conditions that look like dementia.

When levels are normal. For people who are not low, extra B vitamins have not clearly helped. A Cochrane review of 5 trials found no benefit for thinking over 6 to 24 months.¹ A 2022 review of longer studies suggested B vitamins might slow decline when taken early and for a long time. That still needs to be confirmed.¹ Limited research

Safety: Very high amounts of vitamin B6 taken for months can cause serious nerve damage, such as numbness in the hands and feet.¹ More is not better.

Vitamin E

Vitamin E is an antioxidant (a substance that protects cells from a kind of wear and tear). A Cochrane review found no proof that it prevents dementia or improves thinking. One study of moderate quality suggested it might slow the loss of daily skills in people who already have Alzheimer's.¹

Safety: Vitamin E can interact with blood thinners and some other medicines. In a large cancer prevention trial, men taking high-dose vitamin E had a higher risk of prostate cancer.¹ Do not start vitamin E for memory without talking with your doctor.

Multivitamins: the COSMOS findings

COSMOS was a large U.S. trial of more than 21,000 adults. Smaller groups within it had their thinking tested over two to three years.⁶

• COSMOS-Mind (2022) followed more than 2,200 adults aged 65 and older for three years. People who took a daily multivitamin scored better on tests of overall thinking, memory and planning. The effect was strongest in people with a history of heart disease.⁷
• A combined analysis (2024) pooled three COSMOS studies with about 5,200 adults aged 60 and older. The multivitamin gave a small gain in overall thinking and memory. The authors said this was like slowing brain aging by about two years.⁶

What this means. These results are encouraging. But the gains were small, and the studies looked at test scores, not at who developed dementia. The researchers said it is too early to recommend a daily multivitamin to prevent memory decline. They called for larger studies with more diverse groups.⁷ Promising

Ask your doctor whether a multivitamin fits with your other medicines.

Prevagen and the FTC case

Prevagen is a memory supplement sold with TV ads. Its makers said it improves memory and supports brain health in older adults. They said its ingredient, which comes from a type of jellyfish, worked in a clinical study.⁴

In January 2017, the Federal Trade Commission (FTC) and the New York Attorney General sued the maker, Quincy Bioscience. They said the company's own study did not show the promised effect on memory. They also said the company lacked proof for its memory claims.⁴

After seven years in court, including a jury trial, a federal judge ruled in late 2024. The court ordered the company to stop making the challenged claims about memory.⁵ The company appealed. As of late 2025, the appeal was still waiting to be decided by a higher court.¹⁰

The lesson for families: a TV ad, a chart or a mention of a clinical study does not mean a product works. Health claims must be backed by good science.⁵

Medical foods for Alzheimer's

Some memory products are sold as "medical foods." The name sounds official, so it helps to know what it means.

Under FDA rules, a medical food is a specially made product for a disease that has unusual nutrition needs that a normal diet cannot meet. It is used under a doctor's care. It is not a drug and does not go through drug approval.¹¹ A classic example is a special formula for people born with the rare condition PKU.¹¹

Alzheimer's disease does not have a special nutrition need of this kind. So, according to the Alzheimer's Association, no product can properly be labeled a medical food for Alzheimer's.³

One example is Axona, sold for Alzheimer's. Its main ingredient was tested in only one mid-stage trial of 152 people. The maker chose not to run the larger trials needed to prove it works.³ Coconut oil, a cheaper source of a similar fat, has never been properly tested for Alzheimer's.³

Other products you may see

• Huperzine A (from a moss) acts in a way similar to some approved memory drugs. A large U.S. trial found it worked no better than placebo.³ Because of how it works, never combine it with a prescription memory medicine without your doctor's advice.
• Curcumin (from turmeric) has too little and too mixed evidence to say it helps.¹
• Phosphatidylserine has little scientific support, and experts do not recommend it for memory.³
• Coral calcium is mostly ordinary calcium. The FTC and FDA have taken action against sellers over false claims.³

Safety first: supplements and other medicines

Older adults often take many medicines. Supplements can interact with them in serious ways.³ Ginkgo and vitamin E may raise bleeding risk, especially with blood thinners.^1,2

How to spot a memory supplement scam

People worried about memory loss are a prime target for health fraud. The FDA lists these warning signs:¹²

1. One product cures many things. No pill fixes memory, joints, heart and energy all at once.
2. Stories instead of science. Glowing testimonials and online reviews are easy to fake.
3. Quick fixes. Few health problems can be fixed quickly. Be wary of promises of fast results.
4. "All natural" means safe. It does not. Some "natural" products have been found to contain hidden drug ingredients.
5. Miracle words. Phrases like "new discovery," "guaranteed results" and "secret ingredient" are red flags.
6. Conspiracy claims. Ads that say doctors or drug companies are hiding a cure are trying to sell, not inform.

Other tips:

• A real treatment for Alzheimer's would be prescribed by doctors and widely reported, not sold only through ads or social media.¹²
• If you were misled by a product, report it to the FTC at ReportFraud.ftc.gov.⁴
• A person with memory loss can be targeted again and again. See scams and financial abuse for ways to protect them.

What helps instead

Supplements can distract from steps with stronger evidence. Unproven products may also lead people to skip a proper diagnosis and treatment.⁹

• Get a full checkup for memory problems. Depression, medicine side effects, and thyroid, liver or kidney problems can all affect memory. So can low B12.^13,8 Many are treatable. See getting a dementia diagnosis.
• Ask about approved medicines. See dementia medicines for what the FDA has approved.
• Protect your brain health. Read about exercise, blood pressure and heart health, hearing and vision, and staying mentally and socially active.
• Follow real research. See new treatments being tested and joining a clinical trial.

Questions to ask your doctor or pharmacist

Is this supplement safe for me?

• Could it interact with my blood thinner, heart medicine or memory medicine?
• Does it affect bleeding before surgery or dental work?
• Is the amount on the label too high for someone my age?

Do I need it at all?

• Should we check my B12 or vitamin D level first?
• Is there good evidence it helps someone like me?
• Would a basic multivitamin make more sense than a costly "memory" product?

What should we try instead?

• Have we ruled out treatable causes of memory loss?
• Is an approved dementia medicine right for us?
• What daily habits would help most?

Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.