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What Does “Clinically Proven” Mean in Advertising?

What Does “Clinically Proven” Mean in Advertising?

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“Clinically proven!”

You’ve seen the phrase plastered across health products (i.e., nutrition supplements, anti-aging elixirs, and skin care products) and strategically peppered through marketing scripts on the shopping network.

But wait! What the heck DOES “clinically proven” actually MEAN anyway?

There are a number of aspects to consider in answering this question, so I’ll list them out point by point.

“Clinically proven” defined

Within the realm of health product advertising, there is ZERO official definition or regulation of the phrase “clinically proven.”

“Clinically proven” is an ambiguous phrase and can mean different things to different people. It’s often used by marketers to give a deceptive stamp of approval to a product or service which, in many cases, has no legitimate scientific evidence to support its efficacy.

Objective vs subjective evidence

When a product is claimed to be “clinically proven,” your first question should be, “Really? Says who?”

clinically proven supplement
clinically proven bullshit

In the haste to rush to market, some companies may give their supplement, infomercial ab gadget, or balance device to paid social media influencers and then solicit testimonials. Or they run a tiny pilot study with a few people and try to pass this off as “clinical” research. While this may provide suggestive evidence that a product “works,” it can be subject to bias and does not constitute legitimate research.

Real research requires very careful and meticulous planning, experimental design, strict methods, statistical analyses, and interpretation in order to determine if, in fact, any results were due to the intervention (i.e., the supplement or exercise). Have a look at the Consolidated Standards of Reporting Trials statement which gives a deep dive into what is required for conducting and reporting randomised clinical trials.

What is clinical research?

For something to be legitimately deemed “clinically proven,” it must be rigorously evaluated for its safety and efficacy. Pharmaceutical medications and medical devices undergo the strictest of testing before approval for retail sale.

Phase I trials

Phase I trials are often small with (20 to 50 participants) and evaluate the efficacy of different dosages (in the case of medications) and potential for harm or other downstream effects. These are often exploratory in nature with an aim of generating more research hypotheses for future studies.

Phase II trials

Phase II trials include a larger number of participants (up to 100 participants) and may be more focused on looking at a specific population with certain health conditions or diseases. The focus is to gather more preliminary data on the efficacy of the treatment as well as more detailed safety and side effects.

Phase III

Phase III trials are significantly larger and may include hundreds or thousands of participants. Randomised, double blind, and placebo controlled trials provide greater understanding of a treatment’s efficacy, safety, and therapeutic dosage.

Phase IV trials

Phase IV trials are carried out after a treatment has been approved and in use by the public. These provide real-world data on long-term safety and efficacy beyond what could be obtained in comparatively shorter phase I to III trials.

But the thing to remember is that, even now in the year 2024, over-the-counter dietary supplements do not have to undergo the same rigorous testing thanks to the 1994 Dietary Supplement and Health Education Act (which ironically has nothing to do with education). It was a loophole law created by Utah Senator Orrin Hatch and backed by the supplement industry to allow products to be sold without having to be proven safe, effective, pure, or that the potency listed on the label is actually what’s in the bottle.

Were the results published in a journal

Scientists and careful consumers like to see the results of studies published in peer-reviewed medical journals. What does this mean in practical terms? 

It means that the study and all its methods, results, and discussion have been reviewed by experts (peers) in the respective area of research under which that study falls.

Subject experts systematically dismantle the study, rake it over the proverbial coals, and try to blow holes in it, find weaknesses, and expose it for junk science.

If it survives that, then it is accepted for publication (usually with suggested revisions).

The value of this process is that it shows the scientists conducting the research have been rigorous in their experimental protocols and that the research is worthy.

Research that isn’t worth its salt

Sometimes research is conducted but it never appears in a peer-reviewed journal.

There are a number of reasons for this but, in many cases, the work WAS submitted for peer review but was repeatedly rejected by editors.

In other instances, the research was not submitted for review because it may have been a small pilot / feasibility study only meant to generate hypotheses for future, larger studies.

Statistically “significant” but means nothing

Research findings must be put into context – i.e., it must be carefully interpreted and applied to different life situations (i.e., is it relevant?).

Back in the 1990s, I authored a comprehensive review of the marketing claims being made about pyruvate, a dietary supplement being touted as a fat burner, performance enhancer, antioxidant, and cholesterol reducing agent (get the full article PDF here)

However, as I dug into the actual research from which the claims were being derived, I soon realised that it was all marketing sleight of hand. Many of the claims exaggerated the statistics where a seemingly large mathematical difference between pyruvate and placebo actually amounted to a very small and clinically unimportant real world difference. It wasn’t that the marketers were lying, but they were taken out of context and blown far out of proportion.

Research participants

In the case of pyruvate, grandiose weight loss claims were made based on two studies that included participants who were morbidly obese women confined to bed in a hospital metabolic ward for 21 days (except for using the toilet and kitchen) consuming a 500 to 1000 calorie liquid diet (Stanko et al 1992a; and Stanko et al 1992b).

The inherent limitation here is that results from studies with such strictly defined criteria are not readily applicable to the general population at large. Women who are able to eat and move freely and may only have a small amount of body fat to lose will likely have a very different metabolic response to morbidly obese women confined to a hospital bed for three weeks.


Next, the dosages used in the pyruvate obesity studies was quite large compared to what was being offered to consumers.

For example, the women in the study consumed up to 28 grams of pyruvate which was in stark contrast to the smaller 3 – 5 g per day dosages of pyruvate provided by commercial supplements. In short, while it is true that large doses of pyruvate can elicit small changes in body fat in bed-ridden morbidly obese women, these results have not been replicated in free-living healthy weight women.

In 2014, a comprehensive systematic review and meta-analysis of randomised clinical trials concluded that the evidence does NOT convincingly show pyruvate is efficacious in reducing body weight.

Single ingredient vs. whole product

It is quite common for health marketers to cite legitimate research conducted on a single ingredient in isolation and claim that it supports their finished product.

This is an important distinction because testing on a single ingredient is not the same thing as testing on the finished product. In many cases, the finished product has no scientific research whatsoever to support marketing claims. And further to the issue of dosage, while a single ingredient may have research that supports its efficacy in high amounts, including a tiny amount in a multi-ingredient formulation would likely not have the same effect.

Tricks that might fool you

Unregulated jargon

Buyer beware: there is absolutely ZERO regulation of the terms “clinically proven” so crafty marketers have a number of options for hoodwinking the general public.

Junk science

Marketers often cite junk science or irrelevant studies published in a pay-for-play predatory journal.


They cite surveys of “satisfied” users’ subjective opinions. Testimonials do not distinguish if the “results” were from the product or other uncontrolled factors (i.e., they started eating less and exercising more). More dubious, they trumpet paid testimonials which raises other ethical concerns.


They cite legitimate research but the study participants are not relevant to most free-living adults (i.e., morbidly obese women housed in a metabolic ward vs the average woman looking to lose a couple pounds).

Flawed research

They cite a single study which may relate to their product but it has methodological flaws. 


They may cite only the highlights of a study but fail to disclose the limitations listed by the study authors (which might work against their marketing efforts).

Only one study

They cite a single legitimate peer-reviewed study (or an unpublished pilot study), but one single study is not a conclusive body of evidence to go and make sweeping claims that something is “proven” to work.

Check out my Wonder Core Smart article and you’ll see how they ambiguously cite “university lab testing” but provide no details to corroborate this.

Take home message

“Clinically proven” is a popular marketing buzz word but you have to arm yourself with knowledge about the hidden meaning.

As a general rule, “science-y” jargin might sound convincing but, in many cases, it’s just glossy marketing copy meant to sell products. I cover a lot of these claims in my article 37 Bullshit Health Marketing Phrases You Should Ignore.

Bottom line: Trust your instincts.  If a pill, potion, or gadget seems too good to be true, then it probably is.

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Sunday 21st of March 2021

Also, science doesn’t “prove.”

Dr Bill Sukala

Monday 22nd of March 2021

Exactly right. It's all about preponderance of evidence, but that can change over time as new research emerges. But it's hard to explain that level of nuance to the general public who tends to like things neat and clean in shiny boxes ("oooh it's 'clinically proven!'").

Jessica Moore

Wednesday 9th of December 2020

This was great! Can't wait for your upcoming content! What have you got planned for us?

judy hauck

Sunday 5th of May 2019

And, the big deal of all: scientific experiments are not meant to, nor do they, "prove" anything. They simply support an hypothesis or disprove it.

Dr Elbanna

Tuesday 6th of February 2018

from where you obtain "clinically proven certificate"?? for new supplement. and how much does cost? Regards,

Dr Bill Sukala

Tuesday 6th of February 2018

Hi Dr Elbanna, For a new supplement to be clinically proven, you will first need to conduct a very thorough review of the existing medical literature on the active ingredients you intend to study. Then put together a proposal for clinical research and then submit it to an ethics review board with your application for ethics approval. Once you receive that, then you'll need to begin the recruitment process, which can be very long and arduous, but worth it in the end. Then you'll need to conduct your randomised, double-blind, placebo-controlled study on a sufficient enough number of subjects to ensure that you have enough statistical power to detect changes from one group to the other. Then, once you have all your results, you'll need to run statistics on them to determine if there are any statistically significant differences between groups. But statistical significance is only one part of it. You'll also need to determine if those differences are clinically meaningful. For example, if a supplement resulted in blood sugar dropping by 0.2 mmol/L then is this clinically meaningful? Will it result in improvements in overall health of the patients that experienced these improvements. In other words, something can be "statistically significant" but in practical terms, it can still be clinically insignificant. Finally, once you've written your report and acknowledged all the strengths, limitations, and implications for your research, then you will need to submit your manuscript to a peer-reviewed medical journal for review by experts in the area in which your study was conducted. So you'll probably need to have your work reviewed by clinical nutrition researchers who understand the biochemistry of the supplement in question. If your research is valid and isn't junk science, then you'll probably have an opportunity to revise the manuscript for publication. Then you'll resubmit it and hopefully get final approval. Then it will sit in a queue for 6 months to a year and eventually get published. Ideally, you will have multiple studies that you have conducted and published and once you have these published articles in your hand, then these will be your "clinically proven certificates."

Or you could just take the supplements yourself and try to make yourself believe they're doing something so you could claim they are "clinically tested." But if you wrote that on your packaging, then you'd be lying and that is unethical and illegal (i.e., false marketing claims). Invest the time and effort in getting real clinical trials done and then you might have a product with staying power. But if you conduct the research and the supplement is no better than a placebo, then basically pack your bags and move on to the next thing because that supplement is a waste of your efforts. Hope this helps clarify.

Kathy Immelman

Friday 25th of January 2013

Hi Dr Sukala,

I wonder if you have any good examples of these ads that claim "clinically proven" or "scientifically proven"? I'm always searching for interesting new material for my postgrad class in critical reading. Anything you can send me would be much appreciated. Thanks!

Bill Sukala,PhD

Friday 25th of January 2013

Hi Kathy, Thanks for your comment. I have amended the article to include two graphics of "clinically proven." The first one has a single research study in support of an ab slimming belt, but the results mainly apply to localized abdominal strength and endurance and not fat loss. The second image shows how desperate they are to overcome objections by including the terms clinically proven four times. I would also suggest having a look over my article You Are What You Eat But Careful Who Says So Kind regards, Bill