Overcoming Confirmation Bias in Dietary Supplement Marketing

Supplement brands know they can’t utilize anecdotal health benefits without substantiating their claims. However, reliance on anecdotal data about how consumers view supplements is still prevalent.

Supplement brands know they can’t utilize anecdotal health benefits without substantiating their claims. However, reliance on anecdotal data about how consumers view supplements is still prevalent. Often, we hear colleagues in the dietary supplement industry share their personal experiences as though they’re universal. We’ve also seen senior leadership make decisions made based on subjective experience, assuming all humans are rational like they are. They believe if you prefer A to B and B to C, then you should prefer A to C.

Well-known psychologists Amos Tversky and Daniel Kahneman (made famous by Michael Lewis’s bestseller The Undoing Project: A Friendship That Changed Our Minds) would beg to differ by exposing many cases of human irrationality.

For example, Tversky and Kahneman showed the above A to C scenario does not always happen in real life. What it proves is that one or two people acting one way does not mean the majority do the same.

Throughout their careers, Kahneman and Tversky provided many good reasons to conduct quantitative research to evaluate subjective biases.

My colleagues and I at Pure Branding have just completed our 2024 US Supplement Consumer PureSegmentation™ Research report, based on over 2,300 census-balanced quantitative interviews. We can attest that, when it comes to assessing a supplement brand, there are six distinct segments with different attitudes and behaviors. Your supplement brand’s internal decision maker may be represented within one of those six segments, but your target consumer could be in another.


There are many heuristics and biases that influence the way we assimilate and translate information. A heuristic is an approach to problem-solving, like trial and error. The heuristics Kahneman and Tversky applied showed how people make decisions.

One example, the “availability heuristic,” states that, when an infrequent event can be brought quickly to mind, people tend to overestimate its likelihood. An example they used is whether there are more English words with “k” as the first or third letter. Because it’s easier to recall words with “k” as the first letter, you think there are more words beginning with “k.” The truth is otherwise.

Let’s apply that concept to the dietary supplement industry. Who are typical supplement consumers at your local food co-op or Whole Foods Market? Think about it for a minute. When we anecdotally ask that question, most people say natural products consumers are more liberal and alternative in their lifestyle. The availability heuristic is at work here because they think about the store staff and how they dress and act—they think about the old cliché of the Birkenstock shopper or the new cliché of the eco-conscious Gen Z-er.

So what does the data say? In Pure Branding’s census-balanced PureSegmentation research, the US supplement consumer is politically diverse, with 23% identifying as liberal, 32% as moderate, and 30% as conservative.

Because that represents 80% of the over-18 US population, there’s no surprise here. This is where segmentation becomes important. There are two segments who over-index in shopping in natural channels. What are their political leanings?

In one segment, 35% identify as liberal, 26% as moderate, and 27% as conservative. For the other, 25% identify as liberal, 30% as moderate, and 30% as conservative. Although they are more liberal than other segments, there is still a non-liberal majority in both. Don’t pigeonhole them as only shopping in natural channels because, looking at these same segments, they also shop in more mainstream retail channels.

The next time you go to a natural store for your supplement, change your availability heuristic to expect to see more conservative people, and you will probably see all of the “hidden” signals you didn’t notice before.


One bias we see every day is “confirmation bias,” where people look for data or instances that confirm their preexisting beliefs. They don’t give (or don’t want to give) thought to other possibilities that might contradict their beliefs. Anyone who participates in social media experiences this on a daily basis. Anecdotally, we all know humans don’t like being proven wrong.

The specialized world of supplement brands sold through healthcare professional (HCP) offices has relied on confirmation bias for years. In this channel, salespeople visit the offices of medical doctors, chiropractors, acupuncturists, naturopaths, and other integrative practitioners. When they succeed in a sale or develop a long-term relationship with a practitioner, they take note of what worked for that practitioner. Other sales follow, and soon they’ve developed a list of “facts” about what interests or engages practitioners. They hierarchize selling points, and certain “benefits” become part of the “truth.” From this point on, they’re relying on confirmation bias.

In recent years, more and more practitioner brands are selling directly to consumers in other channels, which has created a whole new group of “confirmation bias” issues these professional brands need to test. For example, how critical is being an exclusive brand to sales in the healthcare professional channel? This is definitely a question that sparks opinions within HCP brands, and those who want to sell only through the HCP channel have a confirmed bias toward exclusivity.

In our Integrative Physician Market Landscape 2017 research report, we conducted quantitative interviews of over 1,100 integrative MDs and DOs and asked them the most important factors in determining the supplement brands they carried and recommended. Only 10% said having the brand exclusively available through practitioners was most important. In further analysis, that percent went slightly up for those who relied more on supplement sales for income, but it was still no more than 15%.

Confirmation Bias Depends on Who You Ask

We all experienced the pandemic, but, depending on who you ask, the impact it had on us differs. If you see an integrative healthcare professional, you will have a different experience than if you rely on conventional medicine. Ask a holistic practitioner and a conventional doctor if belief in alternative therapies and trust in the medical establishment has increased or decreased, and you will get an answer based on their individual experiences. Especially in the world of health, people want their individual view to win, which plays out in many ways in the supplement industry.

In our 2024 PureSegmentation research, we wanted to know how much COVID-19 has changed supplement and health behaviors.

We asked survey respondents if, since 2020, their belief in a more holistic view of medicine and healing (body, mind, spirit) has increased, decreased, or stayed the same. One might think that, with the controversies of the last few years, people’s pre-pandemic views would be firmer; those who were more aligned with alternative medicine would be more so, and those who were more aligned with conventional medicine would be more so.

In truth: 56% stayed the same, 30% increased their belief in alternative medicine, and only 6% decreased or doubled down on their belief in conventional medicine. These data indicate that, in the post-pandemic world, the views of those who believe in alternative medicine have intensified. But why?

We asked respondents a similar increase/decrease question about their trust in the medical system, and here only 19% said their trust increased, and 29% said it decreased, with 50% staying the same.  The 30% increase in belief in alternative medicine and 29% decrease in trust in the medical system are perhaps two sides of the same coin.

This data points to a complex impact on beliefs and attitudes. In fact, when you look at the data through the six segments, you see dramatic differences, with some segments actually having more of an increased trust in the medical system and some having more of a decreased trust.

A Final Thought (Courtesy of Kahneman and Tversky)

One of Kahneman and Tversky’s disciples suggested a new definition of “nerd” could be a person who knows his own mind well enough to mistrust it. In other words, when in doubt about a direction your brand should take, look for the data. As Kahneman wrote in his bestseller Thinking, Fast and Slow, “The confidence we have in our intuitive beliefs and preferences is usually justified. But not always. We are often confident even when we are wrong, and an objective observer is more likely to detect our errors than we are.”

It is not uncommon for me or my industry peers to talk to people outside the supplement world and be asked why supplements aren’t regulated. Can they be trusted in light of the most recent negative press about some ingredients? From these conversations, one may get the impression that trust in the supplement industry is low.

We leave you with one last bit of data from our 2024 census-balanced supplement consumer research. We asked respondents about their perceived trustworthiness of the vitamin and supplement industry. Among supplement consumers, 61% think the industry is very trustworthy or trustworthy, and only 7% view the industry as very untrustworthy or untrustworthy. The rest feel neutral.

It’s great when data confirm what you hope for but may not expect.