Every check follows five steps: quote the claim exactly as marketed, identify which regulatory category the product falls into, find the primary source, read what was actually measured, then state a verdict and say where the evidence runs out. Verdicts run from supported to untested, and untested is not the same as disproven.
How does Market Truth check a health claim?
Every check follows the same five steps: quote the claim exactly as marketed, identify which regulatory category the product falls into, find the primary source, read what was actually measured, then state a verdict and say where the evidence runs out. No step is skipped because a conclusion looks obvious.
The order matters. Deciding the answer first and then finding sources that support it is how most health content on the internet gets written, and it is why so much of it is wrong in the same direction.
What counts as a primary source here?
A primary source is the organisation that generated the information, not a site reporting on it. For US health products that means the regulator, the standards body, or the study itself. A manufacturer’s description of its own trial is a marketing document and is treated as one.
| Source | What it can answer | What it cannot answer |
|---|---|---|
| FDA | Regulatory status, device clearance and approval records, warning letters, recalls, required label wording | Whether a supplement works |
| FTC | What substantiation an advertiser must hold, endorsement and testimonial rules, enforcement history | Whether a specific product was substantiated |
| NIH Office of Dietary Supplements | Ingredient-level evidence summaries, intake data, known interactions | Brand-level quality or dosing |
| USP and NSF | Whether a specific product was verified for identity, potency and contaminants | Whether the ingredient produces the advertised benefit |
| Peer-reviewed literature | What was measured, in whom, for how long, and at what dose | What will happen to you specifically |
That last column is the one most health writing ignores. A USP Verified mark is a real and useful signal, and it says nothing at all about whether the ingredient inside the bottle does what the front of the bottle promises. Conflating the two is the single most common trick in supplement marketing.
How does Market Truth weigh conflicting studies?
Study designs are not interchangeable. We apply a standard evidence hierarchy and we tell you which tier a finding came from, because “a study showed” is close to meaningless without it.
- Systematic reviews and meta-analyses of randomised controlled trials carry the most weight, provided the underlying trials are not all from one group.
- Randomised controlled trials come next, weighted by sample size, blinding, duration and whether the outcome measured is the one being advertised.
- Observational and cohort studies can show association and cannot establish cause. We say so every time, rather than letting a correlation quietly become a claim.
- Mechanistic, animal and in-vitro work explains how something might work. It is not evidence that it does work in people, and marketing that leans on it is telling you something by omission.
- Testimonials and before-and-after photos are not evidence. They are advertising, and under FTC rules they carry substantiation obligations of their own.
Three things get checked on every trial we cite: who funded it, whether the dose tested matches the dose sold, and whether the outcome measured is the outcome being marketed. A trial using 600 mg of an ingredient does not support a product containing 50 mg of it, and that mismatch is extremely common.
What does each verdict on this site mean?
Verdicts are deliberately blunt. A hedge that could mean anything is not useful to somebody standing in a shop deciding whether to spend sixty dollars.
| Verdict | What it means |
|---|---|
| Supported | Multiple independent trials in humans found the advertised effect, at a dose comparable to what is sold. |
| Partly supported | Real evidence exists but is limited: small trials, a narrower population, a smaller effect than advertised, or a dose mismatch. |
| Not supported | The claim has been tested in people and did not hold up, or the only supporting evidence is mechanistic, funded by the seller, or absent. |
| Untested | Nobody has run a proper trial. This is not the same as “does not work”, and we do not report it as if it were. |
How often is content updated?
Priority pages are reviewed on roughly a 30-day cycle, and every page carries a visible “last reviewed” date near the byline. Reviewing means re-opening the primary sources, not changing a date. Regulatory status changes, clearances get rescinded, and trials get retracted, so a health page that has not been re-read in two years should be treated as unverified.
Where a page cites a figure that moves, we record when we last checked it rather than writing a month and year into the sentence. A page that says “as of March” ages badly and quietly misleads people who find it later.
How does Market Truth handle corrections?
Corrections are published on the page itself, marked as corrections, and dated. We do not silently edit a page and leave it looking as though it always said the new thing. If a correction changes the verdict, that is stated at the top of the page rather than buried at the bottom.
If you can point at a primary source we misread, email [email protected]. A specific citation gets a fast response. We would rather be corrected by a reader than be wrong in public indefinitely.
What Market Truth will not do
We will not tell you whether to take a specific supplement, whether a device is right for a condition you have, or what your test results mean. That is medical advice, it depends on facts about you that a website cannot know, and it belongs with a licensed clinician.
We will not accept payment, product, or copy approval from a company we cover, and we will not publish a sponsored review. Market Truth is not a government agency and is not affiliated with the FDA, the FTC, the NIH, USP, NSF, or any manufacturer or retailer. Everything here is general consumer information about how health products are marketed, regulated and tested.