Ingredient quantity in Rx drug ad must match product label

AI-verifiedblockerBinding lawCheckable — presence or a literal match settles it

Rule

In an advertisement for a prescription drug that presents ingredient quantity information, the stated quantity for each ingredient must be the same as the corresponding quantity information on the product label. This applies only to advertisements as defined by 21 CFR 202.1 — not to promotional labeling or other non-advertising promotional materials — and only to prescription drugs, not OTC drugs; it does not itself require that quantities be stated, only that if stated they must match.

Check

Confirm the piece is a prescription-drug advertisement (not promotional labeling or another non-advertising format) and, if so, where it states ingredient quantities, compare each stated amount and unit to the corresponding information on the product label; any difference in amount or unit is a violation. Do not flag differences in phrasing or presentation that convey the same amount and unit, and do not apply this rule to promotional labeling, OTC ads, or non-advertising materials.

Escalate when

Escalate if it is unclear whether the piece qualifies as an "advertisement" versus promotional labeling under FDA's distinction; or if the ad and label express the same ingredient quantity in different units (e.g., mg vs. mcg, or a ratio vs. a per-unit amount) and it is unclear after conversion whether the underlying amounts actually match.

Where this comes from

21 CFR 202.1(a)(2). The highlighted words are quoted exactly; a script confirms they appear in the source before the rule can be published.

…mation required by section 502(n) of the Federal Food, Drug, and Cosmetic Act shall appear together, without any intervening written, printed, or graphic matter, except the proprietary names of ingredients, which may be included with the listing of established names. (2) The order of listing of ingredients in the advertisement shall be the same as the order of listing of ingredients on the label of the product, and the information presented in the advertisement concerning the quantity of each such ingredient shall be the same as the corresponding information on the label of the product. (3) The advertisement shall not employ a fanciful proprietary name for the drug or any ingredient in such a manner as to imply that the drug or ingredient has some unique effectiveness or composition, when, in fact, the drug or ingredient is a common substance, the limitations of which are readily recognized when the drug or ingredient is listed by its established name. (4) The advertisement shall not feature iner…

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

Productprescription-drug

Materialadvertisement

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 the operative second command of 21 CFR 202.1(a)(2), a binding 'shall' directed at advertisements, not an example, definition, or preamble gloss. The rule statement is a faithful restatement of it.
- Atomic: (a)(2) contains two independent commands (order of ingredient listing; sameness of quantity information). The rule correctly takes only the quantity-match command, so it is a single checkable requirement.
- Authority correctly 'binding' — 21 CFR is a regulation.
- Determinism defensible as 'deterministic' for the core comparison (ad quantity figure vs. label quantity figure is settled by literal match), but only once the 'wording' element is removed from the check; a phrasing-difference test would turn on judgment.
- Locator 21 CFR 202.1(a)(2) is precise and matches where the quoted sentence sits.
- Severity 'blocker' is defensible: a quantity statement inconsistent with the label is a misbranding exposure under the ingredient-information requirements referenced in 202.1(a), not a cosmetic defect.
- Overstated on scope: applies_when is bare 'promotional', but the source is expressly limited to prescription-drug advertisements — the section is titled '§ 202.1 Prescription-drug advertisements' and its opening sentence defines 'prescription drug' by reference to FDCA 503(b)(1) / § 201.105. Nothing in the excerpt extends the obligation to OTC promotion, promotional labeling, or non-advertising materials.
- Overstated by a missing trigger: the source constrains 'the information presented in the advertisement concerning the quantity of each such ingredient' — i.e., it bites only when the piece actually presents ingredient quantity information. The rule as written carries no such limit.
- Overstated in the check: the source requires the quantity information to 'be the same as the corresponding information on the label'; it does not require identical phrasing. Treating 'any discrepancy in ... wording' as a violation is broader than the text and imports an impression-based judgment into a rule flagged deterministic.
Revised by the drafter
claude-sonnet-5 · 2026-09-21
Independent verification — revise
claude-opus-5 · 2026-09-21
Reviewer's reasons
- Supported: the quoted clause is the operative second half of 21 CFR 202.1(a)(2) — a binding regulatory command ('shall be the same as the corresponding information on the label of the product'). It is not drawn from an example, definition, preamble, or a description of what the rule does not require.
- Not overstated in the rule prose: the statement correctly renders 'shall' as a must, and correctly narrows the trigger to ads that actually present quantitative ingredient information, expressly disclaiming any freestanding duty to state quantities (that duty arises from FDCA 502(n), not from (a)(2)). The prose also correctly confines the provision to prescription-drug advertising.
- Atomic: (a)(2) contains two distinct obligations — order of ingredient listing and equivalence of quantity information. The rule isolates only the quantity-matching obligation and does not bundle the ordering requirement, which is independently checkable and would need its own rule.
- Determinism is correctly 'deterministic': the check is a literal amount-and-unit comparison between two documents; no assessment of prominence, adequacy, or overall impression is involved. The carve-out for equivalent phrasing and the escalation path for cross-unit expressions appropriately route the genuinely non-literal cases to a human rather than forcing a judgment call into a literal test.
- Authority 'binding' is correct — this is a codified federal regulation, not guidance.
- Severity 'blocker' is defensible: an ad quantity that contradicts the label quantity is a direct regulatory violation and a potential safety/misbranding issue, not a stylistic defect.
- Locator '21 CFR 202.1(a)(2)' is accurate; the quoted language appears verbatim in paragraph (a)(2) of the source text.
- applies_when is under-specified relative to both the source and the rule's own prose. The section is titled and scoped to 'Prescription-drug advertisements,' and the rule statement itself excludes OTC advertising, promotional labeling, and non-advertising materials — yet the facets say only product-type 'drug' and promotional 'promotional'. As encoded, the rule would fire on OTC promotional pieces and on promotional labeling, both of which the rule text and the source exclude. This is a missing obvious limit, not an invented one.
Revised by the drafter
claude-sonnet-5 · 2026-09-21
Independent verification — pass
claude-opus-5 · 2026-09-21
Reviewer's reasons
- Directly supported: 21 CFR 202.1(a)(2) states in mandatory terms ('shall be the same') that quantity information in the advertisement must match the corresponding information on the product label. The quote is operative regulatory text, not an example, definition, or preamble.
- Not overstated. The rule preserves the conditional nature of the obligation ('does not itself require that quantities be stated, only that if stated they must match'), which matches the regulation's phrasing ('the information presented in the advertisement concerning the quantity'). It also correctly limits scope to prescription-drug advertisements, consistent with the section heading '§ 202.1 Prescription-drug advertisements' and the section's definition of 'prescription drug'.
- Atomic. The source sentence bundles two obligations — order of ingredient listing and quantity matching — and the rule correctly extracts only the quantity-matching obligation, leaving the ordering requirement to a separate rule.
- Determinism 'deterministic' is defensible: the test is a literal comparison of stated amount/unit against the label, with no dependence on impression, prominence, or adequacy. The one soft edge (equivalent quantities expressed in different units) is properly routed to the escalation clause rather than smuggled into the check.
- Authority 'binding' is correct — this is a codified federal regulation (21 CFR), not guidance.
- applies_when is justified and appropriately limited: promotional, prescription-drug, advertisement. It neither invents a limit nor omits one; the regulation on its face governs only prescription-drug advertisements, and the rule's explicit carve-out of promotional labeling and OTC is consistent with the section's scope.
- Severity 'blocker' is defensible: a quantity statement inconsistent with the approved label is a factual misstatement of composition in a regulated ad and cannot be cured by adjacent context.
- Locator 21 CFR 202.1(a)(2) is precise and matches the quoted sentence.
- Note (non-blocking): the regulation's phrase 'each such ingredient' refers back to the ingredient information required by section 502(n) per (a)(1), so the strictest reading ties the obligation to the required ingredient listing rather than to any incidental mention of a quantity anywhere in the ad. The rule's slightly broader framing ('presents ingredient quantity information') does not create a false positive risk of consequence, since a quantity stated anywhere in an ad that conflicts with the label would be problematic regardless; no change required.

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US-NAME-002