Does Prevagen Work? The Study, the Jury Verdict, and the Federal Injunction

Does Prevagen Work? The Study, the Jury Verdict, and the Federal Injunction

Prevagen's own clinical trial, the only controlled study of its ingredient in humans, did not beat placebo on any of its nine cognitive tests. In February 2024, a federal jury found specific memory-reduction advertising claims misleading. In December 2024, a court barred those memory claims nationwide. Prevagen is still legally sold. The appeal is pending. Here is everything that actually happened, in order.

Key Takeaways

• Prevagen contains apoaequorin, a lab-made protein. Its single clinical trial (n=218) showed no statistically significant improvement over placebo on any measure.
• The company ran more than 30 unplanned subgroup analyses after the main trial failed. Two overlapping subgroups produced borderline p-values, but the probability of at least one false positive across that many tests was roughly 80% (1 − 0.95^30).
• A February 2024 jury found the "clinically shown to reduce memory problems associated with aging" advertising materially misleading. Broader "improve memory" claims were found to lack competent evidence and to have a capacity to deceive, but the jury did not find them "materially misleading." A December 6, 2024 injunction bars those claims.
• Apoaequorin is a protein that is broken down by digestive enzymes. Independent researchers say it is unlikely to survive the gut or cross the blood-brain barrier.
• Prevagen Extra Strength lists at about $59.95 for 30 capsules on the maker's store, roughly two dollars a day.

What Prevagen Is and What It Costs

Prevagen is a dietary supplement whose active ingredient is apoaequorin, a calcium-binding protein originally found in the bioluminescent jellyfish Aequorea victoria. The version in Prevagen is not jellyfish extract. It is a recombinant protein made in a lab.

The supplement comes in capsule form: 10 mg (Regular Strength) and 20 mg (Extra Strength), taken once daily. The NIH's LiverTox database also notes a 40 mg formulation.

If you are evaluating whether it is worth the money, the rest of this page is the evidence you need.

The Madison Memory Study: What It Measured and What It Found

Every Prevagen ad for nearly two decades pointed back to a single clinical trial. Here is what it actually showed.

The Madison Memory Study was conducted in-house by Quincy Bioscience, Prevagen's manufacturer, from December 2009 to April 2011 in Madison, Wisconsin. It was randomized, double-blind, and placebo-controlled. 218 community-dwelling adults aged 40 to 91 with self-reported memory concerns enrolled. 145 received one 10 mg apoaequorin capsule daily; 73 received placebo. 211 finished the 90-day study.

The outcome measures were nine quantitative computerized cognitive tests from the Cogstate Brief Battery, administered at intervals of 8, 30, 60, and 90 days.

The result: no statistically significant difference between the treatment and placebo groups on any of the nine tests.

That is the headline. The company's own study, using its own design, measured nine things and found nothing.

The 30-Plus Subgroup Analyses

After the main trial produced no positive result, Quincy ran more than 30 unplanned post hoc subgroup analyses.

A quick explanation for non-statisticians: a post hoc subgroup analysis means you go back after the study is over and start slicing the data into smaller groups, looking for a pattern that was not part of the original plan. The more slices you make, the more likely you are to find something that looks positive just by chance, the same way flipping a coin enough times will eventually give you ten heads in a row.

Quincy found two overlapping subgroups (participants with AD8 scores of 0 to 1 and 0 to 2, meaning low to mild self-reported impairment) that produced borderline p-values on three of the nine tasks. Those numbers sound impressive in isolation. But with 30-plus unplanned comparisons at a 0.05 significance threshold, the probability of finding at least one false positive was roughly 80% (1 − 0.95^30).

The published write-up appeared in 2016 in Advances in Mind-Body Medicine, a low-profile journal. All four authors were Quincy Bioscience employees at the time. The Alzheimer's Drug Discovery Foundation lists zero meta-analyses, zero systematic reviews, and one clinical trial for apoaequorin, and notes that the trial "did not directly compare the apoaequorin group with the control, thus failing to produce any evidence that apoaequorin worked better than placebo."

If you want to understand why personal testimonials can feel convincing even when trial data shows nothing, the psychology of the placebo effect in supplements is worth reading.

The Digestion Problem

Apoaequorin is a protein. Proteins get broken down into amino acids in your stomach. That is what stomachs do.

The Alzheimer's Drug Discovery Foundation puts it plainly: there is "strong evidence suggesting that apoaequorin does not survive digestion in the gut or cross the blood-brain barrier, so is unlikely to have any effect on the brain."

Joe Schwarcz at McGill University's Office for Science and Society made the same point: proteins are readily broken down during digestion into amino acids and peptides, so the chance of an intact protein reaching brain cells is remote. He also quoted Quincy's own safety study, which reported that apoaequorin "is easily digested by pepsin," the stomach's primary enzyme for breaking down proteins.

So the company's safety data and its efficacy story work against each other. The protein is safe partly because it gets digested. But if it gets digested, it cannot reach the brain intact.

The Legal Timeline

Each entry below is a date and what happened on it. No editorializing, just the record.

• October 16, 2012. The FDA issued a warning letter to Quincy Bioscience. An inspection found records of more than 1,000 adverse events and product complaints reported to the company between May 2008 and December 2011, including seizures, strokes, heart arrhythmias, chest pain, vertigo, tremors, and syncope. Some resulted in hospitalization. As of the inspection, only two had been reported to the FDA. (These are reports the company received. They are not proven to have been caused by the product.) The letter also stated the company was marketing unapproved new drugs.

• January 9, 2017. The FTC and the New York Attorney General filed suit against Quincy Bioscience, alleging deceptive memory and cognitive improvement claims.

• February 20, 2019. The Second Circuit reversed the district court's earlier dismissal and sent the case back for further proceedings.

• February 2024. A federal jury returned a split verdict. It found that the claims Prevagen "reduces memory problems associated with aging" and is "clinically shown to reduce memory problems associated with aging" were materially misleading. It did not find the broader "improve memory" claims materially misleading, though it found they lacked competent evidence and had the capacity to deceive. It also did not find misleading the softer claim about "healthier brain function, a sharper mind, and clearer thinking."

• December 6, 2024. The district court issued a nationwide injunction barring Quincy from claiming that Prevagen can improve memory or cognition, that it can show results within 90 days, and that it is "clinically proven" to work.

• February 26, 2026. A three-judge Second Circuit panel heard oral argument on the appeal. The issues: whether "materially misleading" under New York consumer protection law is a required predicate for broader liability, whether the nationwide injunction is too broad, and whether the New York Attorney General was properly denied the opportunity to seek damages.

• Current status. The Second Circuit heard argument on February 26, 2026. As of September 2026 it had not issued a decision, and the appeal is pending.

Why Prevagen Is Still on the Shelf

The jury's split verdict explains what you see at the pharmacy. The specific memory-reduction claims were found misleading. The softer language about "healthier brain function, a sharper mind, and clearer thinking" was not. That distinction matters.

Visit prevagen.com today and the homepage reads: "Prevagen is an over-the-counter supplement for your brain." It carries the tagline "#1 Selling Brain Supplement Nationwide." The word "memory" does not appear on the homepage. The standard FDA supplement disclaimer is there.

This is the company's adaptation: the marketing has shifted from "clinically shown to improve memory" to vaguer brain-health language that the jury did not strike down. The product itself has not changed.

How Long Does Prevagen Take to Work?

The company's own trial ran 90 days, and the advertising once promised "results within 90 days." That specific claim is one of the statements the December 2024 injunction bars.

There is no established time to effect because there is no established effect. The trial did not show a benefit at 90 days. No independent replication has occurred. Saying it takes 30, 60, or 90 days implies there is a destination. The evidence does not support one.

What to Do Instead if Memory Is the Concern

Two branches here, depending on the situation.

If this is about ordinary forgetfulness, the kind where you walk into a room and forget why, the evidence points to habits, not capsules. Sleep quality, regular aerobic exercise, blood pressure management, hearing checks (untreated hearing loss is a documented risk factor for cognitive decline), staying socially engaged, and a conversation with a clinician about medications and B12 levels. None of that costs sixty dollars a month and all of it has better evidence than any brain supplement on the market.

The AARP Global Council on Brain Health reviewed the evidence and could not endorse any ingredient, product, or supplement formulation designed for brain health. That is not one skeptic's opinion. It is an international expert panel's conclusion after a formal evidence review.

If you want to understand why personal testimonials can feel convincing even when trial data shows nothing, the psychology of the placebo effect in supplements is worth reading.

If the concern is new or getting worse, that is a doctor's appointment, not a supplement decision. Changes in memory that affect daily life, confusion about time or place, difficulty with familiar tasks: these are reasons to see a clinician, not to try a capsule first.

The Bottom Line on the Evidence

Prevagen's single clinical trial did not show it worked. The company's advertising said otherwise for years. A jury found those specific memory-reduction claims misleading, and a federal court barred them. The appeal is pending, and the product remains on sale with softer language.

Whether a supplement is worth trying depends on what the evidence actually shows, not what the advertising once said. For apoaequorin, one company-run trial with 218 people, zero independent replications, and an 80% false-positive probability on the subgroup results that carried the marketing. That is the full picture.

Frequently Asked Questions

Is Prevagen a scam?

"Scam" is the searcher's word, not the legal one. The FTC's term was "deceptive." The case was about advertising claims, not the legality of the product itself. A jury found specific memory-reduction claims materially misleading, and a court barred them. Prevagen is a legal dietary supplement that remains on sale. The issue was never whether selling it is illegal. The issue was whether the advertising matched the evidence. The jury said, on the memory-reduction claims, it did not.

Does Prevagen actually improve memory?

The company's own 218-person trial showed no statistically significant improvement over placebo on any of its nine cognitive tests. The two subgroup results the company cited came from 30-plus unplanned analyses with an estimated 80% false-positive probability. No independent trial has replicated any benefit. The Alzheimer's Drug Discovery Foundation concluded the trial failed to produce evidence that apoaequorin worked better than placebo.

Is Prevagen still legal to sell?

Yes. The December 2024 injunction bars specific advertising claims. It does not pull the product from shelves. Prevagen is classified as a dietary supplement and continues to be sold at pharmacies, retailers, and online. The company has shifted its marketing to language the jury did not find misleading.

How long does Prevagen take to work?

There is no established time to effect because there is no established effect. The company's trial ran 90 days and found no benefit. The claim that Prevagen can "show results within 90 days" is one of the statements the December 2024 court order specifically bars.

Is Prevagen worth the money?

At roughly $2.00 a day for the Extra Strength version, Prevagen costs about $60 a month. The single trial behind it did not beat placebo. Independent researchers say the protein is likely digested before reaching the brain. The AARP Global Council on Brain Health could not endorse any supplement for brain health after reviewing the evidence. Whether that represents value depends on your threshold, but the clinical case for spending the money is not there.

Did the FTC win the Prevagen case?

Partially. The February 2024 jury found the memory-reduction claims misleading but did not find the vaguer "sharper mind" language misleading. The December 2024 injunction barred the memory and "clinically proven" claims nationwide. The New York Attorney General was denied the opportunity to seek damages. Quincy Bioscience appealed. The Second Circuit heard argument on February 26, 2026, and as of September 2026 had not issued a decision.

Where the Evidence Stands

The record on Prevagen is unusually complete: one trial, one verdict, one injunction, one pending appeal. Readers now have access to every major data point and legal development in one place. What happens next depends on the Second Circuit.

A Different Question Than the One Prevagen Was Trying to Answer

Prevagen was built around a daily memory claim, and the courts have now weighed in on whether that claim holds up. Whatever the Second Circuit decides, the product asks a long-horizon question: can a jellyfish protein improve recall over 90 days? That is a fundamentally different question from whether you can stay locked in for a Tuesday afternoon work block.

Roon is not a memory supplement and makes no cognitive-improvement claim. It is a zero sugar sublingual caffeine pouch (80 mg caffeine, 60 mg L-theanine, 25 mg methylliberine, 5 mg theacrine) designed for acute alertness across a 6 to 8 hour window. The 80 mg caffeine dose is well below what the caffeine-and-memory literature typically uses, so do not expect memory benefits. Stop at least 8 hours before bed. Subscriptions start from $9.16 per tin, or as little as $0.61 per pouch. A one-time 4-tin order is $15.00 per tin.

If your goal is long-term brain health, the AARP Global Council's recommendations (sleep, exercise, clinician guidance) remain the evidence leaders. Roon answers a narrower, more boring question: can you hold attention through a long task today?

Written by Roon Team