The State of Supplement Claims · Category report
We ruled the 321 best-selling gut and digestion listings on Amazon US, from 166 brands, against all 109 published standards. 81% fail. 54% of the brands carry at least one Critical finding, a named-condition or disease claim, the highest share of the eight categories we scan. The category has a signature claim: “heals leaky gut”, on the listings of 16 of the 166 brands, and it is a disease claim on its face. 89 of the 166 brands carry a Critical claim, the class that can get a listing suppressed, on listings that were selling when we read them.
Method · every phrase ruled against FDA structure/function, FTC substantiation and marketplace policy · 109 standards, v1.4.1 · scanned 14-27 Sep 2026 · brands never named in public data · free to cite with attribution
Executive summary
Four in five gut listings fail outright.
260 of the 321 listings received a FAIL verdict, 81% against 76% across all eight categories. Only stress scores worse on this measure. These are the bestsellers: probiotics, digestive enzymes, fibre, gut-lining formulas.
More than half of gut brands carry a claim that can take a listing down.
89 of 166 brands, 54%, carry at least one Critical finding. That is the highest share in the database, against 42% overall. 126 listings, 39% of the category, carry one.
The category’s own vocabulary is the problem.
Gut copy is written next to the language of medicine. “Heals leaky gut” appears at 16 brands, a disease term sits in the title or bullets at 34 brands, and “relieves symptoms of” at 37. None of these reads as reckless to the person writing it. Each is a disease claim to the FDA, to Amazon’s policy and to the machines that read listings.
Bloating, reflux, regularity, IBS, leaky gut: the words a gut shopper searches for are the words a regulator reads as a condition. The copy borrows them, and the borrowed words are what the platforms’ AI flags first.
Method and data
Listings enter the database through the same engine that runs our paid audits. Each listing is ruled, phrase by phrase, against all 109 standards in force at the scan, built on FDA structure/function rules, FTC substantiation guidance and Amazon’s supplement claims policy. Every finding must quote the page word for word, and any quote the software cannot find on the page is discarded before it enters published figures. Since 28 Sep 2026 the category also holds every ruled listing from Amazon’s own Best Sellers lists for it. Paid audit verdicts are signed by a licensed pharmacist. Individual brands are never named in public data. The full method and the standards behind it are documented on the Standards page.
The whole-database figures this report is drawn against are in The State of Supplement Claims; the category’s screenshot-ready numbers are on its scorecard.
The verdict split
A FAIL verdict means the listing carries at least one Critical or High finding, a phrase that breaks a published standard seriously enough that the listing as a whole does not pass. FIX THEN PASS means the only findings were Medium or Low. PASS means no findings at all.
Every ruled gut and digestion listing by verdict · 321 listings
12 of 321 listings pass with nothing to fix. A FAIL verdict does not mean the product is unsafe or ineffective; this report measures marketing language, not chemistry. But marketing language is what regulators, platforms and courts read, and by that measure 81% of the category’s bestsellers do not hold up.
Percentages rounded to the nearest point. Counts are exact.
Fail rate by category
Gut and digestion is second on fail rate, behind stress, and first on the share of brands carrying a Critical finding. The two measures answer different questions: how often a listing has something serious to fix, and how often a brand has written a claim that can draw enforcement on its own.
The right-hand column is the share of that category’s brands carrying at least one Critical finding. Rows count every listing ruled in that category; a listing sold into two categories is ruled in each.
Fail means at least one Critical or High finding on the live listing.
The phrase table
Ranked by how many of the 166 brands carry each one. Struck phrases are quoted from live listings. The brands are not named. Their copy names them.
Counts are distinct brands, among the 166 ruled in the category, that carry the phrase or a direct variant. Bars are scaled to the top row.
Six of the ten are the paperwork and default-vocabulary failures found across the whole database: a missing disclaimer, an undocumented Non-GMO claim, an unverifiable GMP badge, a superlative. The gut-specific rows are what make the category the riskiest. “Normalizes” and “restores” (33 brands) describe a return from a disordered state. “Detox” (30) claims a removal of toxins no listing substantiates. And two rows are Critical: a disease term placed in the title or bullets, at 34 brands, and “heals leaky gut” at 16.
The claims that can end a listing
Every Critical finding in the category, grouped by the rule it breaks and counted by brand. The first three rows are the same claim in three positions: a condition named outright, a treatment verb attached to one, and a condition word placed where Amazon’s policy bars it.
Counts are distinct brands with at least one Critical finding of that class. A brand can appear in more than one row.
Inside the findings
Across the 321 listings we logged 1,685 findings. 293 are Critical, 17% of the category’s findings against 9% across the database: a gut finding is twice as likely to be the kind that can end a listing.
Every finding logged in the category, by severity · 1,685 findings
The dated record
The numbers above would matter less if enforcement were theoretical. It is not, and the named-condition claims that define this category are the ones it reaches first.
Four institutions with four different incentives read supplement listings the same way, and the platforms read with machines that keep getting better: Amazon’s AI scans billions of listing changes a day, and Google’s Gemini models read what an ad means. A gut listing that says “leaky gut” is not hiding from any of them.
Sources: FTC penalty schedule and Notice of Penalty Offenses, FDA warning-letter database, Amazon seller policy, public litigation record.
Guidance
This is general information, not legal advice. The data does suggest a clear order of operations.
Take “leaky gut” out of the copy, the product name and the backend keywords.
It names a condition, so “heals”, “repairs” and “for leaky gut” are disease claims wherever they sit, at 16 of 166 brands today. The structure/function form talks about the lining and the barrier as functions of a healthy body, not about repairing damage.
Write “occasional” and mean it.
Occasional bloating, occasional indigestion and occasional irregularity are the FDA’s own structure/function territory. “Relieves symptoms of”, IBS, reflux and lactose intolerance are not, and “relieves symptoms of” is on the listings of 37 brands.
Keep condition words out of titles and bullets first.
A disease term in the title or bullets is one of the two most common Critical findings in the category, at 34 brands, and the title is the first thing Amazon’s scans read on every edit.
Fix the paperwork.
The FDA disclaimer is missing at 101 brands, a Non-GMO claim has no document behind it at 89, and “GMP certified” cannot be verified from the listing at 42. All three cost a sentence or a file, not a reformulation.
Retire “detox”, “restores” and “normalizes”.
Each describes a return from a disordered state and fails a published standard as written, at 30 and 33 brands. “Supports healthy digestion” and “supports regularity” say what the product does without claiming a cure.
Pharmacist-in-the-loop
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Cite this report
Claims Verified, The State of Supplement Claims: Gut and Digestion, Q3 2026
Free to reproduce with attribution. Every figure on this page is recomputed from the database before each release; the method and the standards are published and versioned.
audit@claimsverified.org →Media and methodology questions: audit@claimsverified.org · © 2026 Claims Verified · Data from the claims database, snapshot 27 Sep 2026 · Reproduction with attribution permitted · Cite as “Claims Verified, The State of Supplement Claims: Gut and digestion, Q3 2026” · Not legal advice
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