What a Supplement Facts Label Must Disclose

Every dietary supplement sold in the United States must carry a Supplement Facts panel. The format is governed by the Food and Drug Administration under regulations derived from the Dietary Supplement Health and Education Act of 1994 (DSHEA) and subsequent labeling rules. The panel is not a certificate of quality — it is a disclosure document, and the distinction matters considerably.

This piece covers what the panel is legally required to show, which bodies and compounds are involved in producing and verifying those disclosures, and where the label's authority ends — a boundary that is frequently misunderstood by consumers and sometimes by retailers.

What the Supplement Facts Panel Is Required to Show

Under 21 CFR Part 101, a Supplement Facts panel must include a serving size, the number of servings per container, and a list of every dietary ingredient present in a quantifiable amount. For each such ingredient, the label must state the quantity per serving and, where an FDA-established Daily Value exists, the percentage of that Daily Value one serving supplies.

Ingredients for which no Daily Value has been established — many herbal extracts, amino acids in isolated form, and novel botanical compounds — must still be listed with their per-serving weight, but the "% Daily Value" column simply reads a dagger symbol (†) directing the reader to a footnote stating that no daily value has been established. This is not an error or omission; it is the correct notation under the regulation.

The panel must also identify the part of the plant used when the ingredient is a botanical (e.g., root, leaf, seed), because the same plant species can yield chemically distinct profiles depending on which part is processed. This is directly connected to the question of what actually determines an herbal supplement's potency — a factor the label names but does not measure.

Proprietary blends receive a partial disclosure exemption. A manufacturer may list a blend under a trade name and declare only the total weight of the blend per serving, without revealing the individual weights of each component inside it. The ingredients within the blend must still be listed, in descending order by weight, but the consumer cannot determine from the label alone how much of any single component is present.

Other ingredients — binders, fillers, coatings, flavors, colors, and preservatives — must appear below the Supplement Facts panel in a separate "Other Ingredients" list, but they are not required to carry per-serving weights in that location.

Which Agencies, Compounds, and Processes Govern the Label

The FDA sets the labeling framework and enforces it post-market. Unlike pharmaceutical drugs, dietary supplements do not require FDA pre-market approval. The agency does not review or sign off on a Supplement Facts panel before a product reaches store shelves. Enforcement is reactive: the FDA can act against a product after it is already in commerce if the label is found to be false or misleading, or if the product is found to be adulterated. The broader picture of how the supplement industry is actually regulated clarifies why the label is a manufacturer's declaration, not an agency-verified certificate.

The Federal Trade Commission (FTC) holds parallel authority over advertising claims made about supplements. A claim that appears in advertising — including online product pages — falls under FTC jurisdiction even if the same claim does not appear on the physical label. The two agencies operate under a memorandum of understanding that divides responsibility: FDA owns the label; FTC owns the ad.

Manufacturers and distributors are responsible for ensuring their labels are accurate and that their products meet identity, purity, strength, and composition standards under FDA's Current Good Manufacturing Practice (cGMP) regulations (21 CFR Part 111). These rules require testing of incoming raw materials and finished products, but the test results themselves do not appear on the label. A consumer reading the panel has no direct view into whether those tests were performed, passed, or documented.

Third-party testing organizations — independent certification bodies not affiliated with FDA — may audit a manufacturer's cGMP compliance and test finished products for label accuracy, contaminants, and disintegration. Their involvement is entirely voluntary. When present, their findings are typically represented on the label by a small verification seal, not by any additional data within the Supplement Facts panel itself.

Where the Label's Disclosures Break Down or Mislead

The most common source of confusion is the gap between what a label declares and what a product actually contains. Because no pre-market review exists, a manufacturer can print any quantity on the panel without independent confirmation. Studies published in peer-reviewed journals and by independent testing organizations have repeatedly found products whose actual ingredient weights differ substantially — in both directions — from label claims. The label is a legal statement of intent and composition, but its accuracy is not confirmed by the act of printing it.

Standardization language on herbal products is a related friction point. A label may state that an extract is "standardized to 95% curcuminoids" or "standardized to 50% ginsenosides," but the Supplement Facts panel does not specify the analytical method used to arrive at that figure. Different assay methods can produce different standardization readings for the same physical extract. The label discloses a number; it does not disclose the method behind it.

Serving size is set by the manufacturer, not by the FDA. A manufacturer can define a serving as one capsule or four capsules. Because the % Daily Value calculation depends on the serving size declared, a smaller defined serving can make a nutrient appear to contribute a smaller percentage of the daily value, which may affect how a product is perceived relative to competitors. The regulation requires accurate math within the declared serving, but does not constrain how large or small that serving is defined to be.

The proprietary blend exemption described above means that for any product using such a blend, a consumer cannot determine whether the first-listed ingredient — present in the largest amount — constitutes 90% of the blend's weight or 11%. This is a structural limitation of the disclosure framework, not a labeling error.

Finally, the label says nothing about contaminants. Heavy metals, pesticide residues, microbial contamination, and undeclared pharmaceutical adulterants are not disclosed in the Supplement Facts panel even when they are present. Detection requires laboratory testing that occurs entirely outside the label framework.

What a Verification Seal Shows — and What It Does Not

A supplement verification seal — sometimes called a third-party supplement testing seal — is a mark applied to a label by an independent certification organization after that organization has audited the product or the manufacturing facility, or both. Common seal programs test for label accuracy (does the product contain what it claims, in the declared amounts?), contaminant limits (heavy metals, microbes, pesticides), and in some cases cGMP compliance at the manufacturing site.

What a seal does show: that at the time of testing, the lot or product formula submitted for evaluation met the certifying organization's stated criteria. A seal from a reputable program is meaningful evidence that the product passed a defined set of tests. Understanding how third-party supplement testing actually works reveals that these programs vary considerably in scope — some test every production lot, others test periodic samples — so two products bearing the same seal type may have been evaluated at different levels of frequency.

What a seal does not show: FDA approval (no dietary supplement is FDA-approved before sale), a finding that the product is effective for any purpose, or continuous surveillance of every batch produced after certification. Certification is a point-in-time or periodic assessment, not a permanent guarantee of every unit shipped.

The seal also does not appear within the Supplement Facts panel itself. It sits elsewhere on the label — typically on the front panel or the back near the bottom — and is entirely separate from the required regulatory disclosures. A consumer reading only the Supplement Facts panel will see no trace of whether any independent testing occurred. Conversely, the absence of a seal does not mean a product is inaccurate or unsafe; many compliant products are never submitted to voluntary certification programs.

Structure/function claims — statements such as "supports immune health" or "helps maintain bone density" — may appear on the label near the Supplement Facts panel, but they are not part of it. These claims must be accompanied by a disclaimer stating that the FDA has not evaluated the claim and that the product is not intended to diagnose, treat, cure, or prevent any disease. That disclaimer is a legal requirement, not a manufacturer's choice.

The Supplement Facts panel is a precisely regulated document that answers specific questions about declared ingredients and serving sizes, while leaving a substantial number of quality and accuracy questions entirely unaddressed — questions that can only be answered by laboratory analysis occurring well outside the label's four corners.

Note: This explains how supplements work. This statement has not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease, and it is not a substitute for advice from a physician, pharmacist, or registered dietitian.