The FDA issued a series of warning letters to medical device companies in 2023 tied to advertising, promotion, and off-label claims. Looking across that enforcement record and the patterns that preceded it, the same categories appear repeatedly. Not because companies are trying to deceive anyone, but because the gap between common marketing instincts and what FDA rules actually permit is wider than most marketers realize.

This article maps the safe side and the enforcement side of that gap, by claims category.

The Foundation: Every Claim Must Match the Cleared Intended Use

The starting point for all device marketing claims is 21 CFR Part 801, which governs device labeling, and the FDA's general device labeling requirements. Under this framework, device labeling includes more than the physical label on the device or its packaging. It includes:

Every claim in every one of these materials must be consistent with the device's cleared or approved indications for use. This is the foundational rule that makes all of the specific violations below a variation on the same theme: a claim that exceeded what the regulatory authorization covers.

Claims That Are Safe

Accurate regulatory status claims

Stating your device's regulatory status accurately is the baseline compliant claim. For 510(k) devices, this means "FDA cleared" or "510(k) cleared." For PMA devices, "FDA approved." For De Novo devices, "FDA De Novo authorized" or "De Novo granted." (See the companion article in this cluster for the full regulatory terminology breakdown: https://www.buzzboxmedia.com/blog/fda-cleared-vs-fda-approved-medical-device-marketing/.)

Claims derived directly from the clearance letter

If your cleared indications for use state that the device is indicated for "short-term transcutaneous electrical nerve stimulation for pain relief," you may say the device provides electrical nerve stimulation for pain relief in the indicated context. The language should track the clearance. You do not need to reproduce it verbatim, but it should not expand beyond it.

Technically substantiated performance claims

Performance claims that are supported by the data in your 510(k) submission are generally permissible. If your submission included a specific sensitivity or specificity figure from a performance study, and that figure was accepted by the FDA, you may cite it in marketing materials, provided you also accurately describe what the figure means and where it comes from.

General safety claims tied to the cleared context

"Designed for single-patient use to reduce contamination risk" or "uses no radiation" are general technical attribute claims that are permissible when accurate. They are not claims about efficacy or superiority. They describe what the device does or does not do in a factual, non-comparative way.

The moment you name a competitor or imply you outperform one, a second set of rules applies on top of these. See comparative advertising for medical devices for the evidence standard each type of comparison requires.

Claims That Trigger Warning Letters

Off-label promotion: the most common violation

Off-label promotion means promoting a device for a use, patient population, clinical setting, or condition not covered by its cleared indications. This was a recurring theme in the FDA's 2023 device enforcement. Each of the following is drawn from the text of an actual FDA warning letter:

Patient population expansion. In its May 25, 2023 warning letter to iRhythm Technologies, the FDA cited the company for marketing its Zio AT as a "mobile cardiac telemetry monitor" intended for "near real-time monitoring" of "high-risk patients." The company's cleared product, the Zio QX ECG Monitoring System (K163512), was cleared for long-term monitoring of non-critical care patients where real-time monitoring is not needed. The FDA determined that describing the device for a high-risk, near real-time patient population represented a new patient population requiring a new 510(k). (This letter also cited device changes made without a new 510(k), medical device reporting failures, and quality system violations, so it is not solely a promotion case.) (See https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/irhythm-technologies-inc-643474-05252023.)

New clinical application. In its July 5, 2023 warning letter to Outset Medical, the FDA cited the company for promoting the Tablo Hemodialysis System for continuous renal replacement therapy (CRRT). The device was cleared under K223248 for treatment modalities that did not include CRRT (intermittent hemodialysis, sustained low efficiency dialysis, prolonged intermittent renal replacement therapy, and isolated ultrafiltration, for acute and/or chronic renal failure). The FDA stated that the sale of the Tablo system for CRRT was outside the scope of the clearance and required a new 510(k). (See https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/outset-medical-inc-656485-07052023.)

Condition expansion. In its June 21, 2023 warning letter to ZYTO Technologies, the FDA cited the company because its ZYTO Hand Cradle galvanic skin response device and software, cleared under K111308 only for "the measurement of galvanic skin response," were promoted in a way that identified diseases and conditions including Alzheimer's disease, HIV, Parkinson's disease, and melanoma. The FDA determined the promotion represented a major change to the device's intended use for which the firm lacked clearance, rendering the device adulterated and misbranded. (See https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/zyto-technologies-inc-652316-06212023.)

Pediatric population for adult-only devices. In its August 16, 2023 warning letter to King Systems Corp. dba Ambu, Inc., the FDA cited the company because its website promoted the King LTS-D supraglottic airway with an intended use for pediatric populations, while the cleared indication for use was for adult patients only. The FDA directed the firm to remove the unsupported pediatric performance claims or submit a 510(k) with the proposed indication. (See https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/king-systems-corp-dba-ambu-inc-661617-08162023.)

The pattern is consistent: a cleared device, a marketing claim about a use not covered by the clearance, and a warning letter. The clearance letter is the boundary. When marketing crosses it, enforcement follows.

Unsubstantiated superiority and comparative claims

Claiming that your device is better than a competitor's, or than a previous standard of care, requires head-to-head comparative data. The FDA's concern is not with comparison itself but with claims of superiority that are not grounded in clinical evidence.

Specific violation patterns:

In its May 19, 2023 warning letter to Steiner Biotechnology, LLC, the FDA cited unsupported performance statements on the company's website for its Socket Graft bone grafting material, including claims that the product produces "superior bone quality," delivers an accelerated healing response, and results in "No allergic reaction" and "No inflammatory response." The FDA found no information in the device's clearances (K052493 and K113049) to support these statements, and noted that the company's own biocompatibility study data showed that an inflammatory response occurred. The FDA treated these unsupported performance statements as changes to the cleared device requiring a new premarket submission. (The same letter also cited extensive quality system regulation violations under 21 CFR Part 820, so it is not solely a claims case.) The enforcement action illustrates that positive absolute claims ("no X") require as much substantiation as comparative claims ("better than Y"). (See https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/steiner-biotechnology-llc-651802-05192023.)

"Safe and effective" without specific substantiation

While "FDA approved" devices can invoke the FDA's safety and effectiveness determination (because PMA requires the FDA to make that finding), 510(k) devices may not claim the FDA found them "safe and effective." 21 CFR 807.97 is explicit: a substantial equivalence determination "does not in any way denote official approval of the device." Using "safe and effective" as a general marketing claim for a 510(k) device in a way that implies FDA endorsement of safety and effectiveness creates the same misbranding risk as calling the device "FDA approved."

A factual safety claim based on specific performance data in your submission is different. "In the pivotal study, zero device-related adverse events were reported in 150 patients" is a substantiated factual claim. "Safe and effective" as a standalone marketing headline for a 510(k) device implies an FDA finding that does not exist.

Incorrect regulatory status language

The cleared-vs-approved distinction generates enforcement patterns that are detailed in the companion article in this cluster (https://www.buzzboxmedia.com/blog/fda-cleared-vs-fda-approved-medical-device-marketing/). The short version: "FDA approved" for a 510(k) device, "FDA certified," "FDA validated," and using "FDA registered" as a device-quality claim are all patterns the FDA has acted against.

Testimonials and patient outcome claims

The FTC's Health Products Compliance Guidance establishes that testimonials do not substitute for clinical evidence of efficacy. An individual patient's story about their experience with a device does not constitute substantiation for the device's effectiveness claims across the patient population.

Additionally, the FTC issued revised Guides Concerning the Use of Endorsements and Testimonials in Advertising (16 CFR Part 255) in June 2023 (https://www.ftc.gov/legal-library/browse/federal-register-notices/guides-concerning-use-endorsements-testimonials-advertising-16-cfr-part-255), which updated the framework for disclosures when endorsers have material connections to the company. If a clinician is paid to speak, has equity in the company, or receives anything of value in connection with their endorsement, that relationship must be disclosed.

Practically, this means:

Social media: same rules, different format

The FDA has not created a separate regulatory framework for social media. Social media posts by or on behalf of the company are promotional materials and are subject to the same rules as any other marketing channel.

The practical challenges are real. A tweet or Instagram post does not have room for all required disclosures and accurate indications-for-use context. The FDA has published guidance on presenting risk and benefit information in promotional materials, including those with limited space, and the general principle is that claims must be accurate and complete regardless of format. A post that makes a claim without the context needed to keep it accurate is a problematic claim.

For device companies, this means:

The FTC Dimension

The FDA is not the only enforcement body relevant to device marketing. Under Section 5 of the FTC Act (15 U.S.C. 45), the FTC has authority over unfair or deceptive acts or practices in commerce, including deceptive advertising, and that standard applies to medical devices alongside the FDA framework.

The FTC requires that health-related claims be supported by "competent and reliable scientific evidence," which it interprets as well-designed clinical trials or peer-reviewed research. Testimonials and anecdotal evidence are not sufficient substantiation even if they are genuine.

In April 2023, the FTC sent Notices of Penalty Offenses to about 670 companies in the health-products sector regarding substantiation requirements for product claims, putting recipients on notice of conduct the FTC considers unlawful and the associated civil penalty exposure (https://www.ftc.gov/news-events/news/press-releases/2023/04/ftc-warns-almost-700-marketing-companies-they-could-face-civil-penalties-if-they-cant-back-their). A Notice of Penalty Offenses does not itself mean a recipient violated the law; it establishes the knowledge that can support civil penalties under Section 5(m)(1)(B) of the FTC Act if the recipient later engages in the identified conduct.

The Pattern Behind the Pattern

Reviewing the 2023 warning letters together, a consistent sequence emerges:

  1. A device is cleared for a specific, bounded indication.
  2. The market for adjacent indications is larger or more commercially attractive.
  3. Marketing copy, sales materials, or KOL presentations use language that extends into the adjacent indication.
  4. Sometimes this is intentional; more often it is the result of marketers not having the clearance letter in front of them when they write.
  5. FDA finds the materials and issues a warning letter.

The practical implication is that the clearance letter is a living document in your marketing operation. Not a milestone that the regulatory team files and the marketing team never sees again.

Building a Defensible Claims Process

The device companies that avoid this enforcement pattern consistently have the same thing in common: a clear internal process for claims review before any content reaches a channel. That process does not need to be bureaucratically complex. It needs to answer one question for every marketing claim before it is published: is this claim within the four corners of our cleared indications?

Buzzbox Media works exclusively with medical device and healthcare companies. Our content process includes a regulatory claims review step before anything goes live. If your team is preparing launch materials and wants a second set of eyes on claims compliance, a 30-minute call is the right starting point. Learn more about our medical device marketing services or book at https://www.buzzboxmedia.com/book.

Related Reading in This Series

Frequently Asked Questions

See the full FAQ below.

Sources Cited