Almost everything the label legally has to disclose sits in the Supplement Facts panel and the two lines under it. At Longevity Benchmark, we read the regulation behind every box on the panel before we compare two products. The three parts that look most reassuring, namely a facility registration with FDA, a patent number, and a claim about what the product supports, are the three that carry the least information. The panel is the part that has to tell you something. Federal law governs every box inside the panel. The Food and Drug Administration (FDA) regulates these panels under Title 21 of the Code of Federal Regulations (CFR).
The Verdict
The Architecture of the Supplement Facts Panel
Federal regulations mandate that every packaged dietary supplement display a standardized Supplement Facts panel unless granted a specific statutory exemption.
Under 21 CFR 101.36(a), nutrition labeling must appear on all supplements offered for sale. Paragraph (h) exempts certain small retailers, with annual gross sales to consumers of not more than $500,000 or food sales to consumers of not more than $50,000, along with certain low-volume products and products shipped in bulk. For standard consumer products, the layout follows rigid formatting rules. The title Supplement Facts must use a type size larger than all other print in the panel. It must be bolded and set across the full width. The entire nutrition block sits enclosed within a hairline border.
Internal lines create functional boundaries. The regulation specifies uniform type no smaller than 8 point for standard text. Column headings and footnotes may drop to 6 point. Under 21 CFR 101.36(e)(6), heavy black bars separate distinct categories. One bar sits directly beneath Servings Per Container. Another bar divides nutrients with federal intake benchmarks from other dietary ingredients.
Federal law also mandates four other statements on product packaging. According to FDA guidance, a container must show a statement of identity, net quantity of contents, nutrition labeling, an ingredient list, and the business name and location. The statement of identity and net quantity belong on the principal display panel. The information panel sits immediately to the right. Under 21 CFR 101.5, the business listing must state the manufacturer, packer, or distributor. Phrases such as "Manufactured for" or "Distributed by" indicate that the firm did not produce the physical supplement. The label must also provide a domestic address or domestic phone number for reporting serious adverse events.
Serving Size Rules and the Per-Unit Arithmetic Trap
The declared serving size dictates every quantity listed on the panel and frequently represents multiple capsules rather than an individual dose.
Under 21 CFR 101.36(b)(1)(i), the serving size must use terms appropriate for the product form, such as tablets, capsules, or packets. FDA defines one serving as the maximum amount recommended on the label per eating occasion. If directions state to take 1 to 3 tablets with breakfast, the legal serving size is 3 tablets.
Manufacturers must use the exact term Serving Size. Modifying that title is prohibited. Servings Per Container appears directly below that line. Under 21 CFR 101.36(b)(1)(ii), this line can be omitted only if the net quantity declaration already makes the total servings obvious, such as a bottle containing 100 tablets with a 1-tablet serving size.
Firms may alter column headings to reflect dosing. Under 21 CFR 101.36(b)(2)(i)(A), a brand can choose Each Tablet Contains or Amount Per 2 Tablets. Paragraph (e)(9) permits optional per-unit or per-day columns alongside the required per-serving column. FDA states that "there are no laws or regulations that limit the serving size of a dietary supplement or the amount of a dietary ingredient that can be in a serving." It adds that "this decision is made by the manufacturer and does not require FDA approval."
The arithmetic only collapses when the serving size is a single unit. Take FDA's own example of a label whose directions say to take one to three tablets. The serving size is set at three tablets, so every figure in the Amount per Serving column describes three tablets at once. A 90-tablet bottle then holds 30 servings, not 90. Two products declaring the same number are not the same purchase until you have checked how many units that number is spread across.
| Label Format (FDA's Own Examples) | Declared Serving Size | What the Amount per Serving Column Describes | What One Unit Delivers |
|---|---|---|---|
| Directions say to take 1 to 3 tablets with breakfast | 3 tablets | The three-tablet total, which is the maximum recommended intake | One third of the declared figure |
| Serving Size: 1 Caplet (Multiply amounts by 3 for total daily amount) | 1 caplet | One caplet | The declared figure; the daily total is three times it |
| Optional per-day column headed Per Day (3 Caplets) beside a 1-caplet serving | 1 caplet | One caplet in the serving column, three in the per-day column | The per-serving figure, never the per-day figure |
Amount Per Serving and Elemental Weight Declarations
Quantitative amounts declared on the panel represent the weight of the active dietary ingredient rather than the total weight of the source compound.
Under 21 CFR 101.36(b)(2)(ii), declared weights must reflect the pure dietary ingredient. A panel declaring calcium shows the elemental weight of the mineral rather than the total weight of calcium carbonate. Paragraph (d) allows brands to list source compounds in parentheses immediately following the nutrient, using terms such as "Calcium (as calcium carbonate)". When multiple sources supply one nutrient, 21 CFR 101.36(d)(2) requires listing them in descending order by weight.
Evaluating compound forms matters across categories. In our review of magnesium supplement label evaluation, the chemical form determines elemental yield. Under 21 CFR 101.36(d)(3), manufacturers may declare compendial standards, such as "Calcium (as calcium carbonate USP)". Under section 403(s) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), failing to meet an official compendium standard renders the supplement misbranded.
Extraction rules govern botanicals. Under 21 CFR 101.36(b)(3)(ii)(B), liquid extracts with solvent present must declare total extract weight, written as "fresh dandelion root extract, x (y:z) in 70% ethanol". When solvents are removed, paragraph (b)(3)(ii)(C) requires the dried extract weight. Furthermore, 21 CFR 101.36(b)(2)(i) prohibits declaring zero amounts for nutrients present below 2 percent of reference intakes. The panel cannot list zero values, separating it from standard food labels.
Vitamins and minerals follow a mandatory regulatory order. Under 21 CFR 101.36(b)(2)(i)(B), listings must sequence from Vitamin A, Vitamin C, Vitamin D, and Vitamin E through to Sodium, Potassium, and Fluoride. Beta-carotene may be declared as a percentage share of total Vitamin A.
Percent Daily Value and Reference Intake Standards
Percent Daily Value calculations reflect population-level dietary benchmarks rather than individual nutritional requirements.
Under 21 CFR 101.36(b)(2), Percent Daily Value (%DV) applies to nutrients carrying a Reference Daily Intake (RDI) or Daily Reference Value (DRV). The mathematical formula divides the quantitative weight by the official reference value and multiplies by 100. Calculations use benchmarks set for adults and children four years of age and older. The FDA Daily Value reference table draws these numbers from the highest Recommended Dietary Allowance published by the National Academy of Medicine.
The agency publishes distinct columns for specific populations. Under 21 CFR 101.9(c)(8)(iv), separate RDIs exist for infants, young children, and pregnant women. When products target those groups, column headers must specify the group. As an interpretation rule of thumb, FDA notes that 5% DV or less represents a low contribution, while 20% DV or more represents a high contribution.
Federal revisions modernized these metrics. The final rule published at 81 FR 33742 in May 2016 shifted vitamins A, D, and E from International Units (IU) to metric weights. Mandatory compliance dates were later extended by 83 FR 19619 to January 1, 2020, for large manufacturers and January 1, 2021, for small firms. FDA states that "at this time, all labels should be in compliance with the amended regulations."
According to FDA unit-conversion guidance, conversions differ by chemical form. For Vitamin D, 1 microgram equals 40 IU. For natural Vitamin E (RRR-alpha-tocopherol), the conversion factor is 0.67 from IU to milligrams, whereas synthetic Vitamin E (all-rac-alpha-tocopherol) uses a factor of 0.45. For folate, 1 microgram Dietary Folate Equivalent (DFE) equals 0.6 micrograms folic acid. Niacin references 16 milligrams Niacin Equivalents (NE), declared simply as milligrams.
| Nutrient Name | Current Federal RDI or DRV | Measurement Unit | 2016 Rule Change |
|---|---|---|---|
| Vitamin D | 20 | Micrograms (mcg) | 1 mcg equals 40 IU; IU optional in parentheses |
| Vitamin A | 900 | Micrograms RAE (mcg) | Retinol activity equivalents replace IU |
| Vitamin E | 15 | Milligrams (mg) | alpha-tocopherol replaces IU based on form |
| Folate | 400 | Micrograms DFE (mcg) | Dietary folate equivalents account for source |
| Magnesium | 420 | Milligrams (mg) | Elemental mineral weight required |
| Potassium | 4,700 | Milligrams (mg) | Mandatory under updated nutrition standards |
Asterisked Rows and Ingredients Without Daily Values
Ingredients lacking established federal reference intakes must display an explanatory symbol pointing to the phrase Daily Value not established.
Under 21 CFR 101.36(b)(3)(i), substances without an RDI or DRV are classified as other dietary ingredients. These compounds appear beneath the heavy horizontal line separating vitamins and minerals. Under 21 CFR 101.36(b)(3)(iv), each entry must carry a symbol in the % Daily Value column, typically an asterisk. This symbol refers to a bottom footnote reading "Daily Value not established". Paragraph (b)(2)(iii)(A) permits "Daily Value (DV) not established" when the acronym requires clarification.
No mandated order governs this lower block. Unlike the fixed sequence for vitamins, manufacturers list other dietary ingredients in any order. Common compounds in this category include omega-3 fatty acids, coenzyme Q10, creatine, and botanical extracts. None appear in federal RDI or DRV tables.
Fatty acid profiles illustrate this requirement. In our guide on how to read a fish oil label, total fish oil weight differs from individual eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. Both fatty acids must carry the asterisked footnote. Similar rules apply when examining testing data for creatine gummies and published clinical amounts in our analysis of human trial dosages for NMN. Quantities must reflect the actual compound weight per serving.
Proprietary Blends and Missing Ingredient Quantities
Federal law permits manufacturers to withhold individual ingredient weights by grouping dietary substances into proprietary blends.
The statutory foundation for blends sits in DSHEA section 4, codified at FD&C Act section 403(s)(2)(A)(ii). The law mandates listing the quantity of each ingredient, or, for proprietary blends, the total combined weight of all ingredients. Implementing this, 21 CFR 101.36(c) allows firms to designate blends using terms like Proprietary Blend or descriptive phrases.
Under 21 CFR 101.36(c)(3), the panel displays only the aggregate weight of the blend on the primary line, paired with an asterisk linking to the unestablished Daily Value footnote. Individual components appear indented below. Under 21 CFR 101.36(c)(2), these components must be listed in descending order of predominance by weight. The first substance represents the heaviest component, while the last represents the lightest.
Vitamins and minerals cannot be obscured. Under 21 CFR 101.36(c)(1), any ingredient possessing an RDI or DRV must be listed separately with its specific weight and %DV. Blends can only obscure other dietary ingredients.
The Other Ingredients List and Botanical Identity Rules
Excipients, binders, colorings, and non-dietary substances must appear immediately below or adjacent to the Supplement Facts panel.
Under 21 CFR 101.4(g), non-dietary substances sit outside the nutrition box. The list uses the heading Ingredients unless source ingredients are already identified inside the panel, in which case the heading Other ingredients is required. This line carries excipients, fillers, artificial colors, artificial sweeteners, flavors, or binders.
Botanicals must satisfy distinct identity requirements. Under 21 CFR 101.4(h), common names must match the standardized nomenclature in Herbs of Commerce, 1992 edition. Paragraph (h)(1) requires declaring the specific plant part in English, such as root, leaf, or bulb. The Latin binomial name must appear in parentheses unless already established by Herbs of Commerce. Under FD&C Act section 403(s), omitting the plant part renders the dietary supplement misbranded.
Structure Function Claims and the Mandatory Disclaimer
Statements describing how a nutrient affects human physiological structure or function require a prominent statutory disclaimer on the container.
Under 21 CFR 101.93(c), any product bearing structure or function claims must display this exact text: "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease." Paragraph (e) requires boldface type at least one-sixteenth of an inch high. Paragraph (d) requires the text to sit adjacent to the claim or inside a distinct box linked by a symbol.
Under 21 CFR 101.93(f), claims describe the role of a nutrient intended to maintain bodily structure or function, such as "calcium builds strong bones" or "fiber maintains bowel regularity". Crossing into disease claims subjects the product to drug regulations under paragraph (g). The rule defines disease as damage to an organ or bodily system, or a state of health leading to dysfunction, including hypertension or cardiovascular disease. Manufacturers must file a notification with the FDA Office of Dietary Supplement Programs within 30 days after first marketing, certifying they possess substantiation. The agency does not review this evidence prior to sale.
Authorized health claims operate under different rules. As outlined in FDA labeling guidance, authorized health claims describe disease-risk reduction, such as calcium reducing the risk of osteoporosis. These require premarket review and significant scientific agreement. FDA defines a qualified health claim as one "supported by less scientific evidence than an authorized health claim," and requires that such claims "be accompanied by a disclaimer that explains the level of the scientific evidence supporting the relationship."
| Claim Category | Premarket FDA Review | Scientific Standard | Mandatory Disclaimer Required |
|---|---|---|---|
| Structure/Function Claim | None (30-day postmarket notice) | Manufacturer substantiation | Yes (statutory bold box) |
| Authorized Health Claim | Yes (mandatory authorization) | Significant scientific agreement | No (FDA authorized language) |
| Qualified Health Claim | Yes (premarket evaluation) | Limited scientific evidence | Yes (qualifying evidence text) |
Facility Registration, Good Manufacturing Practice, and Expiration Dates
FDA states that facilities manufacturing, processing, packing or holding dietary supplements "must register with FDA... before beginning such operations," and separately that it "does not have the authority to approve dietary supplements before they are marketed" and "does not test dietary supplements before they are sold to consumers."
Under the Public Health Security and Bioterrorism Preparedness and Response Act of 2002, facilities manufacturing, processing, packing, or holding supplements must register with FDA before operating. Separately, FDA states that it does not approve dietary supplements before they are marketed and does not test them before sale. Furthermore, under FD&C Act section 413, ingredients introduced after October 15, 1994, require a New Dietary Ingredient (NDI) notification submitted at least 75 days before interstate marketing.
Manufacturing practices follow 21 CFR Part 111, published in June 2007. Under 21 CFR 111.3, quality means meeting the manufacturer's own established specifications for identity, purity, strength, and composition. Under 21 CFR 111.75(a)(1)(i), firms must conduct 100 percent identity testing on incoming dietary ingredients. However, finished-batch testing under 21 CFR 111.75(c) applies only to a subset of finished batches based on statistical sampling, unless a firm chooses to test every batch.
Expiration dates are frequently misunderstood. In official labeling guidance, FDA answers directly: expiration dating is not required on dietary supplement labels. When printed, dates must be backed by valid stability data. Part 111 corroborates this by conditioning record retention on the phrase "if shelf life dating is used". Neither storage statements nor expiration dates appear among the five mandatory label elements.
Under 35 U.S.C. 287(a), patent marking is permissive. Its legal function concerns infringement damages rather than product safety or effectiveness.
Published Label Accuracy Data and Third-Party Verification Programs
Analytical testing of retail dietary supplements reveals substantial deviations between declared label values and actual chemical contents.
The National Center for Complementary and Integrative Health (NCCIH) notes that what appears on a supplement label may not match what is inside the product. In JAMA Network Open, a 2023 analysis of sports supplements led by Pieter A. Cohen examined 57 products declaring one of five botanical ingredients: Rauwolfia vomitoria, methylliberine, turkesterone, halostachine, or octopamine. Only 6 products (11 percent) contained an ingredient quantity within 10 percent of the label claim. Twenty-three products (40 percent) contained no detectable amount of the labeled ingredient. Detected amounts ranged from 0.02 percent to 334 percent of declared quantities. Prohibited ingredients were identified in 7 products (12 percent). The authors noted the sample was small, evaluated one sample per brand, and cannot be generalized across all botanicals.
Gummy formulations display similar inconsistencies. In JAMA, a 2023 study of melatonin gummies led by Cohen analyzed 25 products. Twenty-two products (88 percent) were inaccurately labeled. Only 3 products (12 percent) fell within 10 percent of declared melatonin quantities. Measured amounts ranged from 74 percent to 347 percent of label claims. One product contained no melatonin but held 31.3 milligrams of cannabidiol (CBD). The authors cautioned that findings covered only gummies, tested one sample per brand, and may not generalize to capsules.
Independent verification seals provide external testing. The NSF Certified for Sport program screens finished products against 290 banned substances, verifies label contents, and inspects production facilities. The program is recognized by the United States Anti-Doping Agency (USADA), Major League Baseball, the National Hockey League, and the Canadian Football League. LGC Group operates Informed Sport, screening every production batch against over 300 compounds. Label claim confirmation operates under its Informed Protein program.
Consumers evaluating quality marks can review our guide on NSF Certified versus USP Verified certifications. Under 21 CFR 101.36(d)(3) and FD&C Act section 403(s)(2)(D), representing that a product meets an official compendium standard like USP binds the manufacturer legally. NCCIH states: "We encourage you to discuss any decisions about treatment or care with your health care provider."
Frequently Asked Questions
How do you read a supplement facts label?
Start with the declared serving size. Compare it to the total servings in the container. The Amount Per Serving column lists the elemental weight of each dietary ingredient rather than the weight of the raw chemical compound. Nutrients with established reference standards display a Percent Daily Value (%DV) benchmark based on federal intake guidelines for adults and children four years of age and older. Ingredients without federal reference intakes appear in a lower section marked with an asterisk pointing to the statement Daily Value not established. Directly beneath the boxed panel, check the other ingredients statement to identify excipients, binders, artificial colorings, and botanical plant parts. These combined sections define the exact composition of each dose.
What does % Daily Value mean on a supplement label?
Percent Daily Value (%DV) indicates the percentage of a nutrient's federal daily reference intake provided by a single serving of the supplement. Title 21 of the Code of Federal Regulations (CFR) section 101.36 sets the calculation. Manufacturers divide the declared quantitative weight by the Reference Daily Intake (RDI) or Daily Reference Value (DRV), then multiply by 100. The Food and Drug Administration (FDA) bases these reference benchmarks on the highest Recommended Dietary Allowance for adult men and women, established by the National Academy of Medicine. They apply to adults and children four years of age and older. As a general interpretation guide, FDA notes that 5% DV or less represents a low contribution, while 20% DV or more represents a high contribution.
What does "% Daily Value not established" mean?
The phrase Daily Value not established indicates that federal authorities have not set a Reference Daily Intake or Daily Reference Value for that specific ingredient. Under 21 CFR 101.36(b)(3), substances in this category are classified as other dietary ingredients. The regulation requires manufacturers to place a symbol such as an asterisk in the % Daily Value column that links directly to a footnote at the bottom of the panel reading Daily Value not established. Common dietary ingredients that fall into this category include omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), coenzyme Q10 (CoQ10), creatine, nicotinamide mononucleotide (NMN), and botanical extracts. The statement simply means no official population reference intake exists in federal food labeling regulations.
Why do some supplement labels not list the amount of each ingredient?
Manufacturers can omit individual ingredient quantities when grouping substances into a proprietary blend under section 403(s) of the Federal Food, Drug, and Cosmetic Act (FD&C Act). Implemented under 21 CFR 101.36(c), this statutory provision permits firms to declare only the combined total weight of all non-vitamin and non-mineral dietary ingredients in the blend. The label must list the specific ingredients inside the blend in descending order of predominance by weight, showing which substance contributes the greatest share. However, the exact milligram quantity of each component remains undisclosed. Vitamins and minerals with established federal reference intakes cannot be hidden inside a blend. The law requires individual quantitative weights and Percent Daily Value figures for those nutrients.
Does the FDA approve dietary supplements?
The Food and Drug Administration (FDA) does not approve dietary supplements for safety or effectiveness before they enter the commercial market. Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), federal law limits the agency primarily to postmarket enforcement. Unlike pharmaceutical drugs, supplements do not undergo mandatory premarket testing or regulatory clearance before reaching consumers. A manufacturing firm holds legal responsibility under the Federal Food, Drug, and Cosmetic Act for ensuring that its products are safe, unadulterated, and accurately labeled. While facilities must register with the agency before operating, registration is an administrative prerequisite rather than a government verification of product quality. Only specific disease-risk reduction health claims undergo formal premarket review by federal regulators.
Are supplement expiration dates required?
Federal regulations do not require dietary supplement labels to carry an expiration date or shelf-life date. In its official labeling guidance, the Food and Drug Administration (FDA) confirms that expiration dating is not mandatory. However, if a manufacturer chooses to print an expiration date or best-by date on the container, the firm must possess valid stability testing data demonstrating that the claim is not false or misleading. Current Good Manufacturing Practice (cGMP) regulations under 21 CFR Part 111 corroborate this policy by requiring reserve samples and batch records to be retained for one year past the shelf-life date only if shelf-life dating is used. Storage instructions are likewise not among the five mandatory statements required on supplement packaging.
What are "other ingredients" on a supplement label?
The other ingredients line lists non-dietary substances used to manufacture the supplement, including excipients, fillers, artificial colors, artificial sweeteners, flavors, or binders. Under 21 CFR 101.4(g), this statement must appear immediately below or adjacent to the Supplement Facts panel. If a manufacturer lists the source compounds of active nutrients inside the panel, such as calcium as calcium carbonate, those sources do not need to be repeated in the outer ingredient list. For botanical products, federal regulations require the ingredient list to state the standardized common name from Herbs of Commerce and identify the specific plant part used, such as the root, leaf, or bulb.
What does the disclaimer on a supplement bottle mean?
The mandatory disclaimer notifies consumers that the Food and Drug Administration (FDA) has not evaluated the manufacturer's structure or function statements and that the product cannot legally treat medical conditions. Under 21 CFR 101.93 and the Dietary Supplement Health and Education Act of 1994 (DSHEA), any supplement bearing a claim describing how a nutrient supports bodily structure or function must display this statutory text in bold type. The statement clarifies that the product is not intended to diagnose, treat, cure, or prevent any disease. Under federal law, claims regarding disease treatment or mitigation are restricted strictly to approved drug products. Manufacturers must file a notification with FDA within 30 days after first marketing a product bearing structure or function claims.