A new study found that the words on supplement bottles can mislead people. When a fish oil bottle said “supports heart health,” many people thought it could prevent heart attacks—even though that’s not what the label is supposed to claim. Researchers surveyed over 4,000 people and found that supplement labels with health-related phrases often made people believe the supplements could prevent or treat serious diseases. This is a problem because supplement labels are only allowed to say they “support” health, not that they prevent or cure diseases. The study suggests that supplement labels need clearer wording so people don’t get confused about what these products can actually do.

The Quick Take

  • What they studied: Whether the words and phrases on supplement bottle labels make people think the supplements can prevent or treat diseases
  • Who participated: Over 4,400 American adults took online surveys. About half were women, and most were between 18 and 65 years old. They were randomly shown different supplement labels and asked what they thought the supplements could do.
  • Key finding: When a fish oil label said “supports heart health,” 62.5% of people thought it could prevent heart attacks, compared to only 53.9% of people who saw a label with no health claims. Similar patterns appeared with brain health claims and memory benefits.
  • What it means for you: The words on supplement labels may be making you think these products can prevent diseases when they actually can’t. You should be skeptical of supplement claims and talk to your doctor before taking supplements, especially if you have health concerns.

The Research Details

Researchers conducted two separate online surveys with thousands of American adults. In the first survey, people were shown different fish oil supplement labels—some with health claims like “supports heart health” and some with no claims at all. In the second survey, people saw labels for a made-up supplement called Viadin H with different health claims. Each person was randomly assigned to see only one type of label. After seeing the label, they answered questions about whether they thought the supplement could prevent or treat specific diseases like heart attacks, heart failure, and dementia.

This approach is called a “randomized controlled trial” because people were randomly assigned to different groups, and the only difference between groups was the label wording. This helps researchers figure out whether the label words themselves caused people to have different beliefs.

The researchers carefully tracked how many people in each group thought the supplement could prevent or treat diseases, and they used statistics to determine whether the differences between groups were real or just due to chance.

This research design is important because it shows cause and effect. By changing only the label words and keeping everything else the same, researchers could prove that the label wording itself was making people think differently about the supplements. This is stronger evidence than just asking people what they think about supplements in general.

This study has several strengths: it included over 4,400 people, which is a large sample size; it was published in a highly respected medical journal (JAMA Network Open); and it used a randomized design that helps prove cause and effect. However, the study only looked at what people said they believed, not whether they actually bought or used supplements based on these beliefs. Also, all participants were online survey-takers, which might not represent all Americans perfectly.

What the Results Show

The study found clear evidence that supplement label claims confused people about what the products could do. For fish oil, when the label said “supports heart health,” 62.5% of people thought it could prevent heart attacks. This was significantly higher than the 53.9% who thought this when shown a label with no health claims. Similarly, 59% of people who saw “supports heart health” thought fish oil could prevent heart failure, compared to 50.7% of those who saw no claims.

The same pattern appeared with brain-related claims. When people saw “supports cognitive function” on the label, 47.4% thought fish oil could prevent dementia, compared to 39.6% who saw no claims. About 48% thought it could improve memory in people with dementia, compared to 40.5% of those shown no claims.

The results were even more dramatic with the made-up supplement, Viadin H. When the label said “heart health,” 40% of people thought it prevented heart attacks. When it said “brain health,” only 20.2% thought it prevented heart attacks—showing that people’s beliefs changed based on which health claim was on the label. This proves the label words themselves were causing the confusion, not people’s general knowledge about supplements.

The study also found that different health claims on the same supplement led to very different beliefs. For example, with Viadin H, people who saw a “heart health” label were twice as likely to think it prevented heart attacks compared to people who saw a “brain health” label (40% vs. 20.2%). This shows that people are paying attention to the specific words on labels and basing their beliefs on those words, even though the supplement itself was identical.

Previous research has suggested that supplement labels can be confusing, but this study is one of the first to clearly show how specific label words influence what people believe supplements can do. The findings support concerns that have been raised by health regulators and consumer protection groups about supplement labeling. This research adds solid evidence to the debate about whether current supplement label rules are working as intended.

The study only measured what people said they believed, not what they actually did. People might say they think a supplement prevents disease but not actually believe it strongly enough to change their behavior. The study also only looked at online survey-takers, who might be different from people who don’t take online surveys. Additionally, the study used a made-up supplement (Viadin H) in one survey, which might not reflect how people respond to real supplements they’ve heard of. Finally, the study was done in the United States, so the results might not apply to other countries with different supplement regulations.

The Bottom Line

Based on this research, here are evidence-based recommendations: (1) Don’t assume that supplement label claims mean the product prevents or treats diseases—the words “supports” or “promotes” are not the same as “prevents” or “cures.” (2) Talk to your doctor or pharmacist before starting any supplement, especially if you have health concerns or take medications. (3) Be skeptical of supplement marketing and look for scientific evidence from clinical trials, not just label claims. (4) Remember that supplements are not regulated as strictly as medicines, so they don’t have to prove they work before being sold.

Everyone who takes supplements or is thinking about taking them should care about this research. This is especially important for older adults who take multiple supplements, people with chronic diseases who might be tempted to try supplements instead of proven treatments, and anyone who makes health decisions based on supplement labels. People should NOT use supplements to replace proven medical treatments for serious diseases like heart disease or dementia.

If you decide to take a supplement based on label claims, you should not expect to see health benefits quickly. Most supplements take weeks to months to show any effects, if they work at all. However, the more important timeline is this: talk to your doctor before starting any supplement and give them time to evaluate whether it’s safe for you and whether it might interact with other medications you take.

Want to Apply This Research?

  • Track supplement purchases and label claims: Record the name of each supplement you consider, the specific health claim on the label (e.g., ‘supports heart health’), and whether you discussed it with your doctor before taking it. This helps you notice patterns in marketing claims and reminds you to get professional advice.
  • Before buying any supplement, take a photo of the label and send it to your doctor or pharmacist with a message asking: ‘Is this supplement safe for me and does it actually work for what the label claims?’ This simple step can prevent you from being misled by label wording.
  • Create a monthly check-in where you review which supplements you’re taking and why. For each one, write down: (1) What the label claims it does, (2) What scientific evidence actually supports, and (3) Whether your doctor recommended it. This helps you stay aware of whether you’re being influenced by marketing rather than science.

This research shows that supplement labels can be misleading, but it does not mean all supplements are ineffective or unsafe. Some supplements have scientific evidence supporting their use for specific purposes. However, supplements are not regulated as strictly as medicines and do not have to prove they work before being sold. Always talk to your doctor or pharmacist before starting any supplement, especially if you have health conditions, take medications, or are pregnant or breastfeeding. Do not use supplements to replace proven medical treatments for serious diseases. The findings in this study reflect what people said they believed, not necessarily what they actually believe or what would happen if they took the supplements.