No superiority suggestion via 'does not contain'/potency claims absent adequate support

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Rule

In a prescription drug advertisement, a statement that the drug differs from or does not contain a named drug or category of drugs, or that it has greater potency per unit of weight, may not be used to suggest that the advertised drug is safer or more effective than that other drug or drugs. This is violative if the suggestion is made either (a) falsely or misleadingly, or (b) without substantial evidence or substantial clinical experience supporting the safety/effectiveness superiority — either condition alone is sufficient to violate the rule.

Check

In any prescription drug advertisement, find claims that the drug 'differs from' or 'does not contain' a named competitor drug/category, or claims of greater potency per unit weight. Determine whether the claim suggests the advertised drug is safer or more effective than the named drug. It is a violation if that suggestion is (a) false or misleading on its face, OR (b) not supported by substantial evidence (adequate and well-controlled investigations) or substantial clinical experience — the claim need only fail one of these two independent tests to be a violation.

Escalate when

Whether the claim actually implies safety/effectiveness superiority (beyond a literal factual statement) is ambiguous, or whether the cited support rises to 'substantial evidence' or 'substantial clinical experience' is unclear or borderline.

Where this comes from

21 CFR 202.1(e)(6)(xvi). The highlighted words are quoted exactly; a script confirms they appear in the source before the rule can be published.

…gnificant or dissimilar studies in a way that suggests either that such “statistics” are valid if they are not or that they are derived from large or significant studies supporting favorable conclusions when such is not the case. (xv) Uses erroneously a statistical finding of “no significant difference” to claim clinical equivalence or to deny or conceal the potential existence of a real clinical difference. (xvi) Uses statements or representations that a drug differs from or does not contain a named drug or category of drugs, or that it has a greater potency per unit of weight, in a way that suggests falsely or misleadingly or without substantial evidence or substantial clinical experience that the advertised drug is safer or more effective than such other drug or drugs. (xvii) Uses data favorable to a drug derived from patients treated with dosages different from those recommended in approved or permitted labeling if the drug advertised is subject to section 505 of the act, or, in the case of other drugs, if the dosages employed were different from those recommended in the labeling and generally recognized as safe and effective. This provision is not intended to prevent citation o…

Open the original at these words on ecfr.gov ↗Read our full copy →

Document: 21 CFR 202.1
Version: 2026-09-16 — the link above is pinned to this date, so it shows the text as it stood then
Retrieved: 2026-09-21 from www.ecfr.gov
Fingerprint: a542640a872b3f2702d549e8…

Applies when

Naturepromotional

How this rule was checked

Citation proven by script and passed an independent verifier running on a different model. Not yet confirmed by a human.

Drafted
claude-sonnet-5 · 2026-09-21
Independent verification — revise
claude-opus-5 · 2026-09-21
Reviewer's reasons
- Supported: the quote is verbatim from 21 CFR 202.1(e)(6)(xvi), which sits inside the operative list introduced by 'An advertisement for a prescription drug is false, lacking in fair balance, or otherwise misleading, or otherwise violative of section 502(n) of the act, among other reasons, if it:'. This is a binding prohibition, not an example, definition, or description of what is not required, so the rule statement follows from the source.
- Overstated on scope: the source provision is expressly limited to advertisements for prescription drugs, but applies_when is bare 'promotional', which extends the rule to promotional labeling, OTC products, and other non-advertising materials that paragraph (e)(6) does not reach.
- Overstated on the substantiation standard: the source says 'without substantial evidence or substantial clinical experience' — two alternative bases, both defined in (e)(4)(ii)(b)-(c) within this same excerpt. The rule statement and check omit 'substantial clinical experience', so a claim properly supported by documented clinical experience would be wrongly flagged.
- The rule also converts the source's disjunctive trigger ('suggests falsely or misleadingly OR without substantial evidence or substantial clinical experience') into a single conjunctive condition ('falsely/misleadingly suggest, without substantial evidence'), further narrowing the trigger relative to the text.
- Atomic: the two claim forms (differs-from/does-not-contain, and greater potency per unit of weight) are governed by one shared test and one consequence in a single regulatory clause, so this is a single checkable requirement rather than bundled requirements.
- determinism 'judgment' is correct: liability turns on whether the claim 'suggests falsely or misleadingly' superiority, an impression question that no literal match or presence/absence test settles. The escalate-when note correctly identifies this.
- authority 'binding' is correct — 21 CFR 202.1 is a codified regulation, not guidance.
- Locator 21 CFR 202.1(e)(6)(xvi) matches the quoted subparagraph exactly. Severity 'blocker' is defensible because conduct within (e)(6) renders the advertisement violative of section 502(n) of the act.
Revised by the drafter
claude-sonnet-5 · 2026-09-21
Independent verification — pass
claude-opus-5 · 2026-09-21
Reviewer's reasons
- Supported: the quote is the operative text of 21 CFR 202.1(e)(6)(xvi), sitting under the chapeau '(6) Advertisements that are false, lacking in fair balance, or otherwise misleading. An advertisement for a prescription drug is false ... or otherwise violative of section 502(n) of the act, among other reasons, if it:'. It is an enumerated prohibition, not an example, definition, or preamble commentary, so a requirement framing is proper.
- Not overstated: the regulation states a categorical consequence (the ad 'is' false/misleading/violative), so the mandatory framing is faithful rather than an upgrade of hortatory language. The rule's disjunctive reading — violation if the superiority suggestion is either false/misleading OR unsupported by substantial evidence/substantial clinical experience — tracks the 'suggests falsely or misleadingly or without substantial evidence or substantial clinical experience' construction. The rule statement's opening sentence ('may not be used to suggest ... safer or more effective') would be too broad standing alone, since a truthful and substantiated superiority suggestion is not barred by this clause, but the immediately following sentence and the Check both supply the qualifier, so the rule as a whole is not broader than the source.
- Scope limit is correct and present: both the rule statement and the Check confine application to prescription drug advertisements, matching (e)(6)'s 'An advertisement for a prescription drug'. The coarse applies_when value 'promotional' is not contradicted by the source given that the narrower limit is carried in the rule text.
- Atomic: the three triggering claim types ('differs from', 'does not contain', 'greater potency per unit of weight') are alternative predicates of one single prohibition with one test (does it suggest unsupported or false safety/effectiveness superiority). A reviewer runs one determination, not several independent ones.
- Determinism 'judgment' is right: the outcome turns on whether a literal factual differentiation claim 'suggests' superiority and on whether cited support 'rises to' substantial evidence or substantial clinical experience — both impression/adequacy questions, not presence/absence matching. The escalate-when language correctly names exactly these two judgment points.
- Authority 'binding' is right: this is a codified FDA regulation, and (e)(6) ties violation to misbranding under section 502(n) of the act.
- Severity 'blocker' is defensible: violation of an (e)(6) enumerated provision renders the ad false/misleading and violative of 502(n), i.e. a misbranding exposure, not a stylistic defect.
- Locator '21 CFR 202.1(e)(6)(xvi)' matches the quoted subparagraph exactly as it appears in the source text.
- The Check's parenthetical gloss of substantial evidence as 'adequate and well-controlled investigations' is consistent with the definition carried in the source's (e)(4) clause ('substantial evidence of safety and effectiveness, consisting of adequate and well-controlled investigations, including clinical investigations'), which (e)(6) incorporates by cross-reference.