The Drug Facts panel: what it must tell you, in what order, and what it cannot

The back of an OTC box is the only place in American retail where the layout of the information is itself the regulation. Not the content of the information — the layout. There is a federal rule that tells a manufacturer which heading comes first, which comes second, that the active ingredients and their purposes have to sit side by side, that the bullets have to be solid squares or solid circles, and that the type may not run more than 39 characters to the inch. That rule is 21 CFR 201.66, and it applies to every over-the-counter drug product in the country.

Most people read the panel the way they read anything else: eyes to the thing they came for. That works, but it leaves the panel’s main advantage unused. Because the order is fixed, the position of a statement tells you what kind of statement it is — and the regulation draws distinctions between the headings that the headings themselves do not spell out.

The order is the regulation

Section 201.66(c) lists what has to appear and says it has to appear in the order listed. Nine items, and one of them is optional:

#	Heading	What it must contain
1	Drug Facts	The title. If the panel runs onto another side of the box, the continuation is titled “Drug Facts (continued)”.
2	Active ingredient(s)	The established name of each active ingredient and the quantity per dosage unit. Products marketed without discrete dosage units — topicals are the regulation’s own example — state the proportion instead.
3	Purpose(s)	The general pharmacological category or principal intended action of the product, or of each active ingredient.
4	Use(s)	The indications for that specific product.
5	Warning(s)	The categories described below.
6	Directions	The directions for use from the applicable OTC monograph or approved drug application.
7	Other information	Anything required by a monograph that does not fit headings 2–6, 8 or 9 — including the sodium statement described below.
8	Inactive ingredients	The established name of each inactive ingredient, in alphabetical order unless the product is also a cosmetic.
9	Questions?	A telephone number. Optional.

Two things about this table are worth pausing on. The first is that headings 2 and 3 are required to be adjacent, with the active ingredients left-justified and the purposes right-justified — a deliberate two-column design so you can read an ingredient against its purpose without hunting. Where a product has more than one active ingredient, they are listed alphabetically, and where two ingredients share a purpose the purpose need not be repeated as long as the layout makes the association clear.

The second is that the panel is allowed to break across panels, but it may not break out of order. The regulation requires the continuation to retain “the required order and flow of headings, subheadings, and information,” and requires a visual graphic — an arrow, typically — to signal that the panel continues on the next face of the box. So if you find “Directions” on one side and “Inactive ingredients” on another, the jump between them is not a gap. Something is in between.

The warnings are a triage ladder, not a list

This is the part of the panel that most rewards knowing the structure. The regulation does not just require warnings; it sorts them into categories with fixed subheadings, and the subheadings are graded. Reading them in order is reading a decision tree:

• “Do not use” — the regulation calls these contraindications absolute. Its own words: they are “intended for situations in which consumers should not use the product unless a prior diagnosis has been established by a doctor or for situations in which certain consumers should not use the product under any circumstances regardless of whether a doctor or health professional is consulted.” This is the one heading where the regulation contemplates no consultation.
• “Ask a doctor before use if you have” — preexisting conditions and symptoms. The regulation’s framing is that these are “intended only for situations in which consumers should not use the product until a doctor is consulted.” A step down from absolute, and the step is the whole point of the heading.
• “Ask a doctor or pharmacist before use if you are” — this is where all drug-drug and drug-food interaction warnings go. Note the pharmacist: the regulation treats a pharmacist as sufficient for interactions, which is a statement about what kind of question an interaction is.
• “When using this product” — the side effects you may experience, and the substances or activities to avoid while using it.
• “Stop use and ask a doctor if” — the signs of toxicity or other reactions that require immediately discontinuing use.

Above that ladder sit the warnings that are not situational at all: the “For external use only” line for topicals, the Reye’s syndrome warning for salicylates, the allergic-reaction and asthma alerts, the flammability and water-soluble-gums warnings, the liver and stomach-bleeding warnings, the sore-throat warning, the sexually-transmitted-diseases alert for vaginal contraceptives containing nonoxynol 9, the sodium-phosphate dosage warning, the “Keep out of reach of children” warning and the accidental-overdose warning. Each of those is required to follow a specific subheading, in bold, in a fixed place.

The practical consequence: a warning’s position tells you how much room you have. A condition listed under “Do not use” is not a “check with someone” item. A drug listed under “Ask a doctor or pharmacist before use if you are” is a conversation, not a stop. People who read only the words and not the headings tend to flatten all of them into the same level of alarm, which is either frightening or nothing.

“Inactive” is a legal term, not a claim about safety

The single most misread word on the panel. The regulation defines an active ingredient as “any component that is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body.” An inactive ingredient is then defined, at (b)(8), as “any component other than an active ingredient.”

That is the whole definition. Everything that is not intended to do the drug’s job is inactive — the binder, the coating, the dye, the filler, the flavor. The word is a statement about regulatory intent, not about tolerance, and the regulation attaches no warning to it. Two further facts follow from the text:

Only names are required, never amounts. Heading 8 requires “a listing of the established name of each inactive ingredient” — and if the product is not also a cosmetic, they are listed in alphabetical order. Alphabetical order means the position of an ingredient on the list tells you its first letter and nothing else. A sensitizing dye that happens to start with A sits above an inert filler that starts with Z. There is no way to infer quantity, or even rough proportion, from where a name falls.

“Regardless of the source” cuts both ways. The sodium rule at 21 CFR 201.64(b) requires the sodium content per dosage unit to state “the total amount of sodium regardless of the source, i.e., from both active and inactive ingredients” — the anti-caking agent counts, not just the drug. The threshold for printing the number is 5 milligrams or more in a single maximum recommended dose, and above 140 milligrams in the labeled maximum daily dose a warning is required: “Ask a doctor before use if you have a sodium-restricted diet.” If you are on a sodium restriction, this is the one line on an OTC panel that connects directly to the rest of your diet — and it sits under “Other information,” a heading that reads like the fine print and is not.

“Use” is a closed list

Heading 4 carries “the indication(s) for the specific drug product,” and heading 6 carries the dosing from the applicable monograph or approved application. Both are bounded by a document that exists somewhere else — a monograph, or an approved application — and the panel is a window onto it.

What that means in practice: if what you want to treat is not under “Use,” the label has nothing to tell you about it. Not a dose, not a duration, not a warning. The regulation governs labeling, and its enforcement provision is aimed at the product — paragraph (g) makes a non-compliant product “subject to regulatory action” — not at what a buyer does with the box. What leaving the labeled indication costs you is information: you have left the only part of the package that was written for your situation. This is also why the “Purpose” line is worth reading before the “Use” line: the same molecule can appear in products sold as pain relievers, as sleep aids and as cold remedies, and the purpose is what tells you which document the panel is a window onto.

The format rules that explain the box in your hand

A handful of the specifications in paragraph (d) account for most of what a reader notices about the physical panel:

• Directions become a table at three age groups. Paragraph (d)(9) requires the directions to appear “in a table format when dosage directions are provided for three or more age groups or populations.” If a children’s product’s dosing looks like a grid rather than a sentence, that is the rule, not a design choice.
• Small type has a trigger. If the required content would occupy more than 60 percent of the total surface area available to bear labeling, paragraph (d)(10) switches to a reduced set of specifications — headings may drop to 7-point, leading may fall below 0.5-point so long as ascenders and descenders do not touch, and the box may be replaced by color contrast. The content requirements do not shrink. The type shrinks.
• Nothing else is allowed inside the box. Paragraph (d)(7) bars graphical images — a UPC symbol is the regulation’s own example — from appearing in or interrupting the required content, and restricts hyphens to punctuating compound words.
• The bullets are specified. Solid squares or solid circles, 5-point, one shape throughout the panel.
• Type is capped at 39 characters per inch, the title and headings are bold italic, subheadings are bold, and the type is all black or one color on a contrasting background.

There is also an escape hatch, and it is worth knowing it exists: paragraph (e) lets FDA exempt or defer specific requirements on the basis that they are inapplicable, impracticable, or contrary to public health or safety — by FDA’s own initiative or on written request — with requests directed to Docket No. 98N-0337. And paragraph (g) states the back end plainly: a product that is not in compliance with these format and content requirements “is subject to regulatory action.”

Where the panel stops

Three things it will not tell you, and the reason is structural rather than conspiratorial:

1. How much of an inactive ingredient is in there. Names, alphabetically. No amounts, ever.
2. Whether the product interacts with the specific drug you already take. The interactions the label carries are the ones the monograph or approved application required, filed under “Ask a doctor or pharmacist before use if you are.” Your prescription is not in that document. A pharmacist can read both.
3. Whether it is stronger than the brand next to it. The panel gives you the established name and the quantity per dosage unit of each active ingredient, which is enough to compare two products ingredient for ingredient — but the regulation does not require the label to make the comparison, and it will not.

One line the panel does carry that most people never read: for products marketed under an approved drug application whose packaging does not include a toll-free number for complaints to the manufacturer or distributor, paragraph (c)(5)(vii) requires the text “You may report side effects to FDA at 1-800-FDA-1088,” in at least 6-point bold, to appear immediately after the “Stop use and ask a doctor if” subheading. The condition is narrow — a product that carries its own complaint number is not required to print the FDA line — so the absence of the number is not evidence that reporting is unavailable. But where it appears, it is a real, free channel, and it is printed on the box.

What this page does not cover

Federal labeling requirements for OTC drug products only, as set out in 21 CFR 201.66 and the sodium provision at 201.64. It does not cover prescription drug labeling, which is governed by a different part of the same title; dietary supplements, which are labeled under different rules and are not required to carry a Drug Facts panel; or the monographs themselves, which are where the indications, the dosing and most of the warnings actually originate. The regulation cited is the current text; the section has been amended repeatedly since 1999, and the format rules in particular have been revised more than once, so a claim about a specific type size or threshold is a claim about the current text rather than about the label on an older box in your cabinet.