U.S. Structure/Function Claims: File 403(r)(6) in 30 Days, Keep COAs

A structure/function claim describes how a nutrient or dietary ingredient affects the body’s normal structure or function, such as “calcium supports bone strength.” Making one legally requires two things every time: notify the FDA within 30 days of first marketing the claim, and print the mandatory disclaimer on the label. Skip either step, and the manufacturer carries the compliance risk, not the FDA.

TL;DR:

• Companies must notify the FDA within 30 days of first marketing a structure/function claim and include a disclaimer on the label to avoid compliance risks.
• Strong substantiation for claims generally comes from human trials or systematic reviews, while anecdotal or animal studies are insufficient.
• Marketing claims must stay consistent across labels and advertising, as discrepancies or implied disease treatment can trigger enforcement actions.
• Keeping detailed claim files, including substantiation documents and notification confirmation, is essential for regulatory audits.
• Third-party testing with recognized accreditation provides the most reliable verification of supplement ingredients and potency.

Table of Contents

• What the Law Actually Says About Structure/Function Claims
• How to Notify the FDA Under Section 403®(6)
• What Counts as Real Substantiation
• Where FDA Labeling Rules Meet FTC Advertising Rules
• A Launch Checklist for Compliant Claims
• What Happens When Companies Get This Wrong
• Checking the Claims Behind What You Buy
• Why Compliance Is a Business Advantage, Not Just a Legal Hurdle
• Where to Find Third-Party Tested Products and Verification Tools
• Primary Sources Worth Bookmarking
• Sources
• FAQ

What the Law Actually Says About Structure/Function Claims

The Dietary Supplement Health and Education Act (DSHEA) of 1994 added section 403®(6) to the Food, Drug, and Cosmetic Act, carving out a category of claims that supplement makers can use without pre-market FDA approval. That’s the trade-off: structure/function claims move faster than health claims, but they come with strict guardrails.

21 CFR 101.93 spells out what’s permitted, requires the disclaimer, and mandates the notification. The regulation also lists ten criteria FDA uses to tell a legitimate structure/function claim from an illegal disease claim in disguise.

Conventional foods play by a different rulebook. A cereal box can say “fiber maintains bowel regularity” without the disclaimer or notification supplements require, because conventional food claims fall under a separate provision. Confusing the two frameworks is a common and costly mistake for companies expanding from food into supplements.

How to Notify the FDA Under Section 403®(6)

The 30-day clock starts the moment a product carrying the claim first reaches the market, not when the label gets designed or the notification gets drafted. Miss that window, and the product is technically misbranded, even if the science behind the claim is solid.

A compliant notification needs these elements:

1. Manufacturer or distributor name and business address
2. The exact text of the structure/function claim as it appears on the label
3. The product name
4. The name of the dietary ingredient the claim concerns
5. A signature certifying the company has substantiation showing the claim is truthful and not misleading

Companies can file electronically through FDA’s submission portal or mail a written notification. Electronic filing generates a faster confirmation record, which matters during an inspection. Keep that confirmation in a permanent file. A useful habit: build an internal filing checklist that tracks every claim, its notification date, and its confirmation number in one place, so nothing slips past the deadline when a new product launches.

What Counts as Real Substantiation

FDA has never published a single evidentiary bar every structure/function claim must clear. That absence puts the burden squarely on manufacturers to show a claim is truthful and not misleading using whatever evidence actually supports it.

Strong substantiation typically draws on human clinical trials, well-regarded systematic reviews, or a combination of mechanistic data paired with human outcomes. Weaker support tends to fall apart under scrutiny:

• Testimonials or anecdotal reports with no clinical backing
• Animal-only studies presented as if they prove a human effect
• Unpublished or misread preliminary data stretched into a firm claim
• In vitro results alone, with no bridge to how the compound behaves in the body

Retain every substantiation document, lab report, and Certificate of Analysis for as long as the claim stays on the market, plus several years after, and audit that file at least annually.

Pro Tip: Build a “claim file” for each marketed statement that pairs the claim’s exact wording with its substantiation, notification confirmation, and dated review history. Inspectors ask for this file more often than most companies expect.

Where FDA Labeling Rules Meet FTC Advertising Rules

FDA governs what goes on the label. The FTC governs how the product gets advertised, and a claim that clears FDA’s labeling bar can still land a company in FTC trouble if the marketing around it oversells the science.

Context changes everything. A label that says “supports joint comfort” stays inside structure/function territory. A social ad using the same phrase next to a testimonial about “reversing arthritis” pushes the claim into disease-treatment territory the label alone never touched. Product names, imagery, and surrounding copy all factor into how regulators read intent.

A short cross-channel review checklist helps catch this before launch:

• Compare label claim wording against website product descriptions line by line
• Screen social ad copy and influencer scripts for disease language the label doesn’t use
• Check that testimonials and before/after imagery don’t imply treatment or cure
• Confirm the disclaimer appears anywhere the claim is repeated in marketing, not just on the physical label

A Launch Checklist for Compliant Claims

Getting a structure/function claim to market cleanly follows a fairly predictable sequence:

1. Draft claim language that describes a body function, never a disease, symptom, or condition
2. Gather and document substantiation before the claim ever appears on a label or ad
3. File the 403®(6) notification within 30 days of first marketing and save the confirmation
4. Print the exact statutory disclaimer on the label, positioned near the claim
5. Audit every advertising and digital asset for consistency with the label and FTC exposure

Pro Tip: Treat the notification as a paperwork requirement, not a stamp of approval. FDA doesn’t review or endorse the claim when it receives the filing; the notification is purely informational, which means the substantiation burden never leaves the manufacturer’s hands.

What Happens When Companies Get This Wrong

Enforcement runs from a warning letter up through mandatory recalls, import holds at the border, and FTC actions targeting deceptive advertising. None of these outcomes require the company to have acted in bad faith. Sloppy paperwork is enough.

The failures that show up most often: a missing or altered disclaimer, wording that implies treating or curing a named disease, substantiation that wouldn’t survive a second look, and notifications filed well past the 30-day window. Regulators weigh the full picture when judging an implied disease claim, including the product’s name, its packaging imagery, and the tone of supporting marketing copy, not just the sentence printed on the label.

Checking the Claims Behind What You Buy

A Certificate of Analysis tells you whether a product actually contains what the label promises. A useful COA verifies compound identity through methods like HPLC or GC testing, confirms potency against the labeled amount, and sets limits for contaminants such as heavy metals and microbial content. The batch number on the COA should match the batch on your product, and the lab issuing it should carry recognized accreditation.

That last point matters more than most shoppers realize. A lab with ISO or ILAC accreditation follows standardized testing protocols that a random in-house lab doesn’t have to meet, which is why independent lab testing carries more weight than a manufacturer’s own internal numbers.

A few habits make label claims easier to verify before you buy:

• Ask for the current COA, not one from a different production batch
• Cross-check the ingredient list against label claims rather than trusting front-of-package language alone
• Look for a stated third-party testing partner, not just a vague “lab tested” badge
• Use a transparency checklist to compare sourcing claims across brands

Why Compliance Is a Business Advantage, Not Just a Legal Hurdle

Structure/function claims exist because Congress wanted supplement makers to describe real physiological benefits without forcing every product through the years-long health claim review process. That flexibility is a gift, and plenty of companies squander it by writing claims their evidence can’t support.

The manufacturers who treat substantiation and disclaimer language as core to the product, not paperwork bolted on after formulation, spend less money on legal cleanup later. Transparency isn’t a marketing angle. It’s what keeps a warning letter from ever landing in the inbox. Write the claim your data actually proves, not the one that sounds best in an ad.

— Mycelia Link Industries

Where to Find Third-Party Tested Products and Verification Tools

Mycelia Link sells third-party tested research peptides and functional mushroom supplements built around the same transparency principle this article has been laying out: a claim is only as good as the paperwork behind it.

Every product ships with documentation buyers can actually check, rather than a label claim they have to take on faith. If you’re comparing sourcing practices across brands, the Transparent Supplement Sourcing Checklist walks through exactly what to look for in a COA and a testing partner before you buy. For a closer look at how independent labs verify potency and purity claims, the third-party testing benefits guide breaks down what those results mean in practice. Browse the mushroom supplement lineup to see the documentation standard applied to a full product line.

Primary Sources Worth Bookmarking

• FDA: Structure/Function Claims — the agency’s own overview of what’s permitted and required
• 21 CFR 101.93 — the regulation defining permitted statements and disease-claim criteria
• FDA Small Entity Compliance Guide — plain-language filing steps for smaller manufacturers
• CRS Report R48623 — legal analysis of substantiation standards and enforcement gaps

This article is general information, not a substitute for advice from a qualified doctor. Consult a qualified healthcare professional about your own circumstances before acting on anything here.

Sources

• Structure/Function Claims | FDA
• 21 CFR 101.93 — Certain types of statements for dietary supplements
• Food and Dietary Supplement Labeling Claims: FDA regulation and select legal issues | CRS

FAQ

Are structure/function claims regulated by the FDA?

Yes. FDA oversees them under 21 CFR 101.93 and requires a 403®(6) notification within 30 days of first marketing, plus a mandatory disclaimer on the label.

What is a structure/function claim?

It’s a statement describing how a nutrient or dietary ingredient affects the body’s normal structure or function, such as supporting bone density or maintaining healthy circulation, without claiming to treat or cure a disease.

What is the difference between a health claim and a structure/function claim?

A health claim requires FDA review and significant scientific agreement before use, while a structure/function claim only requires manufacturer substantiation and a timely notification, with no pre-approval needed.

What are the three types of claims the FDA allows?

FDA recognizes structure/function claims, nutrient content claims (like “high in fiber,” which requires meeting a set daily value threshold), and health claims, each carrying a different evidentiary and procedural burden.

Does an FDA notification mean the agency approved the claim?

No. The notification is an informational filing, not an endorsement, so the manufacturer still bears full responsibility for the claim’s accuracy and substantiation.

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