What Are the Side Effects of Prevagen?

Prevagen is a popular but also controversial supplement. Quincy, the company that makes it, claims Prevagen can help with age-related memory loss and cognitive decline. Whether or not that’s backed by science is debatable. Below we cover what to know about taking it and the potential side effects of Prevagen to be aware of.

An Overview of Prevagen

Prevagen is one of many supplements that claim to help people improve their memory, particularly when it’s declining due to aging.

This over-the-counter supplement also claims to generally help your brain health, but it’s not FDA regulated, as is the case with other supplements.

The supplement is available as an oral capsule or a chewable tablet.

The primary ingredient is apoaequorin, which is a protein that’s found in some types of jellyfish. The type of apoaequorin in Prevagen is lab-derived, and the supplement also contains vitamin D3.

In lab experiments, apoaequorin acts like a protein naturally present in our bodies called calmodulin. Calmodulin is thought to play a key role in memory.

Age-related problems with learning and memory are related to neuronal calcium dysregulation in the brain. In particular, researchers have found too much calcium in the brain’s neurons contributes to age-related decline.

The protein in Prevagen binds to calcium, so it can help maintain calcium homeostasis, promoting better neuron cell function.

Animal studies show that treatment with apoaequorin helps with memory and performance-related behaviors.

The clinical efficacy in humans isn’t as clear.

In the Madison Memory Study, which was double-blinded, randomized, and placebo-controlled, 218 adults were included. They had self-reported issues with memory and other cognitive concerns. The population of the study was between 40 and 91, without a history of cognitive illness. A total of 211 study participants completed it.

In that study, Prevagen improved some cognitive function measures but also had no discernable effect on many others.

Quincy Bioscience, the company that makes Prevagen, also co-sponsored the study.

There are issues noted with the study, though.

  • First, it only ran for 90 days. That doesn’t give us any key information about the long-term effectiveness or safety of the supplement.
  • The population used in the study is also smaller than what’s generally used to test medications.
  • The third problem is that the tests researchers used to test memory aren’t standard assessments healthcare providers use to look for memory loss conditions. That makes the results of the study harder to interpret.

Perhaps one of the most problematic issues with Prevagen is that while, in theory, it could be effective in regulating calcium in the brain and help memory, it’s thought to be broken down primarily in the human GI tract. That means not much, if any, of it will make it to cross the blood-brain barrier, which it needs to do to have memory benefits.

Prevagen Side Effects

While there may be some issues with the effectiveness of Prevagen, if you do decide to use it, you probably wonder if it’s safe.

First, Prevagen is not an FDA-approved medication. That’s true of all supplements. The FDA doesn’t regulate supplements in the United States. That means safety testing is pretty limited in many cases.

You shouldn’t take Prevagen if you have dementia or Alzheimer’s.

Apoaequorin has undergone some safety testing for toxicity, and in human clinical trials, it appears to be well-tolerated for up to 90 days. In animal safety studies, it was safe even when consumed in doses much higher than what’s recommended and far higher than what’s included in Prevagen.

Currently, apoaequorin isn’t a known allergen, and it’s not thought to be cross-reactive with any allergens.

According to MedicineNet, the supplement is “possibly safe” when taken by mouth and if you follow the package dosage instructions. User-reported side effects of the supplement include dizziness, nausea, headache, anxiety, and problems sleeping.

Rarely some side effects have been reported related to the heart and nervous system, but there’s a lack of evidence to make this connection for sure.

The amount of vitamin D in Prevagen is also something to consider as you weigh the potential side effects. Many older people are deficient in the fat-soluble vitamin, so the fact that it’s included could be beneficial, but make sure you’re not getting too much from other sources. 

If you get too much vitamin D and it builds up in your fat cells, it can lead to hypercalcemia and other side effects.


If you decide to try Prevagen for your memory and cognition, the reports of side effects are minimal, but there’s also limited clinical research. Talk to your doctor before you try Prevagen or any other supplement. There are also some prescription medicines available that can help memory and cognitive decline, so you can also speak to your doctor about those.

Leave a Reply

Your email address will not be published.