How to read a Supplement Facts panel in about sixty seconds

The Supplement Facts panel is a legal document printed in small type on the back of a pack. It is complete, and not designed to be read quickly. This is the order to read it in, and the four places the useful information hides.

The panel is complete. That is not the same as clear.

Credit where it is due: this is one of the better pieces of consumer regulation on a shelf. Its contents and layout are set by federal rule — 21 CFR 101.36 — and a brand cannot omit a line because the number is unflattering.

What the rule does not require is that the panel be easy. It permits a complete, lawful panel that still leaves a shopper unable to answer the question they came with: how much of the thing I want is in here. Once its fixed shape is familiar, though, the panel reads in under a minute.

Flat annotated panel diagram, cream ground, six forest-green callout lines, clean line work
Figure 1 Six regions, and only two of them get read The panel has a fixed anatomy. The regions people skip — the footnote, the parentheses and the line beneath the box — carry most of what separates one product from another. Layout per 21 CFR 101.36. Illustrative panel, not a specific product.

Read it in this order

Not top to bottom. The first two lines rescale every number underneath them, so they come first.

  1. Serving size
  2. Servings per container
  3. The word inside the parentheses, for the ingredients you care about
  4. The amount column, and its units
  5. The %DV column and its footnote
  6. Other Ingredients, beneath the box

Line one: the serving size

Everything in the amount column is per serving, and a serving is whatever the manufacturer says it is — frequently more than one capsule.

Two numbers that have to be multiplied

A panel reading 300 mg against an ingredient, at a serving size of three capsules, says that three capsules together contain 300 mg. It does not say each one does — and that misreading moves the number by a factor of three.

Macro crop, top two printed lines of a panel, matte paper, soft window light
Figure 2 The two lines that rescale everything below them Amounts are stated per serving. Where a serving is three capsules, one capsule carries a third of every figure printed underneath. Per-serving declaration required by 21 CFR 101.36. Illustrative crop.

What it makes comparable

Two products can print identical amount columns and still differ, because one delivers them in two capsules and the other in four. Serving size is what makes cost per day comparable.

Line two: servings per container

Capsule count is a marketing number. Servings per container is the honest one, and the division is worth doing out loud.

Sixty capsules at two per serving is thirty servings — a month. At three per serving it is twenty, and the pack runs out on the twentieth day whatever the front of it implies.

Horizontal bar chart, three bars, cream ground, forest-green bars, no gridlines
Figure 3 The same capsule count is three different products A sixty-capsule pack lasts sixty days at one capsule per serving, thirty at two and twenty at three. Price per pack is not price per day until this division is done. Arithmetic on the servings-per-container declaration required by 21 CFR 101.36.

The parenthesis is where the form lives

Most ingredients in the panel are a name followed by a parenthetical, and the parenthetical does more work than the name.

"Zinc (as zinc picolinate)" and "Zinc (as zinc oxide)" are one line on a shelf and different chemistry in a capsule. So are "Vitamin B12 (as methylcobalamin)" and "(as cyanocobalamin)".

Choline is the clearest case: the word beside it — alpha-GPC, citicoline, choline bitartrate — separates three researched compounds. That comparison is worked through in alpha-GPC vs choline bitartrate.

The amount column, and its units

Milligrams and micrograms are a thousandfold apart and set in the same type. Read the unit before the number — on vitamins, micrograms are normal and milligrams would be remarkable.

The %DV column, and the dagger

The right-hand column gives the amount as a percentage of the Daily Value — a reference figure fixed in federal rule, not chosen by the brand.

When a percentage appears

When the ingredient has a Daily Value. Zinc's is 11 mg, so 15 mg prints as 136%. Vitamin B12's is 2.4 mcg, so 500 mcg prints as a figure in the tens of thousands of per cent.

Why a huge percentage is not a boast

A four-figure percentage against a B vitamin usually means the reference figure is very small, not that the dose is large. The percentage is arithmetic, not a claim.

When a dagger appears instead

Many ingredients have no Daily Value, and the rule then requires a symbol pointing to a footnote reading "Daily Value not established". Alpha-GPC has none, nor does L-theanine, nor a mushroom extract.

So a dagger is not a demerit. It is the panel saying, correctly, that no reference figure exists — which leaves the reader to go and find the research population.

Macro crop, panel footnote line and dagger symbol, shallow depth of field, matte paper
Figure 4 A dagger means no reference figure exists Where an ingredient has no Daily Value, the rules require a symbol referring to this footnote. Most botanical and amino-acid ingredients carry one. Footnote requirement per 21 CFR 101.36. Illustrative crop.
Two-branch flow diagram, cream ground, forest-green rules, generous white space, no icons
Figure 5 Every row goes one of two ways An ingredient with a Daily Value gets a percentage. One without gets a symbol and a footnote. There is no third option and no discretion for the brand. Illustrative diagram of the declaration rules in 21 CFR 101.36.

The line that legally withholds amounts

Several ingredients bracketed under a name and one combined weight is a proprietary blend, and the amounts inside may stay unstated.

The rule is 21 CFR 101.36(c): components in descending order of weight, one total declared, no requirement to give the split. A 500 mg blend of six ingredients could be almost entirely the first, or almost entirely the last.

There is a real argument for blends, stronger than it first sounds. It is set out, with the arithmetic that defeats it, in what a proprietary blend actually hides.

Macro crop, panel section headed Proprietary Blend, indented names, one figure right-aligned
Figure 6 One number standing in for six A blend declares its components in descending order of weight and a single combined total. The split between them is not required. Disclosure permitted by 21 CFR 101.36(c). Illustrative crop.

Where a standardisation percentage hides

For a botanical or a mushroom, the weight is half the specification. The other half is what that weight was standardised to contain, and it sits in the parentheses in the smallest type on the pack — when it is there at all.

"Lion's mane extract 400 mg" and "lion's mane extract (fruiting body, standardised to at least 25% beta-glucans) 400 mg" are the same weight and different information. Which number matters is covered in the one number to look for on a mushroom supplement.

Typographic diagram, one panel row set large, forest-green underline under the brackets only
Figure 7 The specification sits inside the brackets Plant part and standardisation percentage are declared within the parenthetical. Two products can share a milligram figure and differ on what it contains. Illustrative row, formatted per 21 CFR 101.36.

Other Ingredients: the line beneath the box

Anything that is not a dietary ingredient sits outside the panel under "Other ingredients", in descending order of weight: capsule shell, flow agents, colourants.

Most of it is unremarkable

A powder that will not flow does not fill a capsule evenly, and an unevenly filled capsule is worse than one containing a flow agent. This line is not a list of sins.

The two entries worth a second look

The capsule material, because HPMC is plant-derived and gelatin is not — a dietary question rather than a quality one. And colourants: a capsule that gets swallowed does not need to be white.

Macro crop, Other Ingredients line beneath a panel's lower rule, soft directional light
Figure 8 The line outside the box Non-dietary components are declared here rather than in the panel, in descending order of weight. Capsule material and colourants are the two most often worth reading. Declaration required beneath the panel by 21 CFR 101.4(g). Illustrative crop.

What each line can and cannot tell you

Line What it establishes What it cannot
Serving size How many capsules the amounts refer to Anything about a single capsule
Servings per container Days of supply, and so cost per day Whether the pack is good value
Parenthetical Chemical form, plant part, standardisation Which lot it came from
Amount Weight per serving, if not inside a blend How much is absorbed
%DV The amount against a federal reference figure Anything, where no reference figure exists
Dagger footnote That no Daily Value has been set Whether the amount matches any research
Blend total A ceiling for every ingredient inside it The amount of any one of them
Other ingredients Capsule material, excipients, colourants Manufacturing standard or testing

What the panel cannot tell you at all

Whether the pack contains what it says: that is a certificate of analysis for the specific lot, a document a buyer has to ask for.

And whether the amount matches research in people resembling the buyer. Trials in healthy adults and trials in people with a diagnosed condition produce different numbers, and the panel cannot mark which one a figure came from.

The sixty-second run-through

  • Ten seconds — serving size and servings per container. Divide.
  • Ten seconds — scan for a blend. If there is one, every amount inside it is unknown.
  • Twenty seconds — the parentheses on the two or three ingredients that made you pick the pack up.
  • Ten seconds — units. Milligrams or micrograms.
  • Ten seconds — the Other Ingredients line.

This does not establish whether a product works. It establishes what is being bought — the question the panel can actually answer.

A worked example, and what the aisle looks like afterwards

Run it on the panel we print ourselves. Two capsules per serving, thirty servings in a sixty-capsule pouch, so one pouch is one month. No blend line. Every ingredient carries its form in brackets, the mushroom row carries a plant part and a beta-glucan floor, and zinc and B12 show percentages while the other three carry daggers. That is the entire panel on Weal Focus, checkable line by line against any other pack on the shelf.

Afterwards the aisle looks much the same, and a blend on a panel is not evidence of bad faith. What changes is the question. Instead of comparing front-of-pack promises, which are written by marketing departments and are not comparable, you are comparing five facts printed under legal obligation.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Sources for every figure, with the population studied in each, are on our citations page.