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How To Determine if a Supplement Is Worth Your Money Part I: The Example of Prevagen

Updated: Nov 23, 2023

As you get more familiar with the concept and practice of the Medical Bullshit Detector (check out part I and part II), you will start to see that there are a lot of products and resources out there (books, supplements, news stories…) that smell like BS. Many times, simply knowing that something is likely BS may be enough for you to avoid the product and move on. But there are other situations where you really want to know whether something is BS or not. How can you tell?

Prevagen is a popular supplement that is marketed to improve thinking and memory, and in both direct and indirect ways, to treat or prevent dementia. For many people, dementia is one of the most fearsome diagnoses imaginable, and anything that has any chance of reducing this risk would be welcome. I believe a big part of the popularity of this supplement is the fear that it taps into, such that people are willing to shell out $500 or more a year if there is any chance it could help. So, is there any chance Prevagen works?

Looking at the package, it claims to “support healthy brain function, sharper mind and clearer thinking.” This rather vacuous claim smells of BS, but it also states on the package that Prevagen “has been clinically shown to help with mild memory loss associated with aging” and that its “active ingredient, apoaequorin, is safe and uniquely supports brain function.” This sounds impressive. But is it true?

At this point, you can do one of four things:

  1. Go to the company’s website. Hint: 10 out of 10 companies say their product works on their website. If your goal is to convince yourself or others, this is a fine option. If your goal is to find the truth, go elsewhere.) 

  2. Read Amazon product reviews. (Hint: at best, you’re getting anecdotes, but these can sometimes be useful, particularly the low-star reviews; at worst, you’ll find fake reviews meant to sell the product – see this, this, and this.)

  3. Go to an independent website to see what smart people who don’t work for Quincy Bioscience (the makers of Prevagen) have to say. This can be a good option if you are short on time and if the product you’re interested in has been reviewed. A quick search on Google can take you to several reliable outside sources including Consumer Reports, Consumer Lab, and numerous academic sites (e.g. Harvard) stating in no uncertain terms to stay away from this supplement.

  4. Track down the published study or studies that are purported to support the claims of the product's safety and efficacy. I recommend using PubMed for this purpose and will have a later blog on its use. PubMed is a search engine for published research and is considered the gold standard for such searches. Many times you will find that: 

  5. There are no published studies. This could be because it’s never been studied or because the quality of the studies was so poor that they couldn’t be published. Either way, this is always a bad sign and means that the safety and efficacy of the product are unknown. Stay clear of this product.

  6. The published studies are in obscure journals that are not listed on PubMed or were only presented at a meeting and were never truly published. This is also a bad sign. Scientists generally try to get their work into the most prestigious journals that will publish them. The editors and reviewers at high-quality journals will generally reject studies that they believe are unimportant or poorly done. 

  7. The published studies do not directly address the claims for the product in people. Most commonly this means that the study cited by the manufacturer was done in animals, done in cells, or has little to do with the health claims of the product. As discussed in prior blogs, animal studies do not guarantee human safety or effectiveness (in fact they do a pretty poor job of predicting what will work in people). It’s amazing to me how often BS products think that naïve consumers won’t take the effort to track down the study.

  8. There is a study done in people! In our next blog, we will look at the one published Prevagen study to make our minds up for ourselves as to whether or not it really works.

Take Home Points:

  1. For products or books that you don’t care too much about, the Medical BS detector can steer you away from obvious BS.

  2. For products that are important to you, you may want to dig deeper.

  3. Don’t rely on the manufacturer’s website or Amazon reviews to tell you the truth.

  4. There are several independent sources on the internet that can provide you with reliable information including on supplements (e.g. Consumer Reports, Consumer Labs), “experts” (e.g. Quackwatch).

  5. PubMed can help you to find out whether there are any published studies on the product that test its claims. If there are not well-done studies in people, stay away from the product as its safety and effectiveness are not established (particularly if the people trying to sell it to you want you to believe that it is safe and effective).


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