FTC and FDA Marketing Claims: What US Sellers of Wellness Devices Can and Cannot Say

This is one of the most consequential compliance topics for anyone selling wellness devices into the US market, and one of the easiest to get wrong without ever intending to — because the line between an accurate physical description and a regulated medical claim is often a matter of a few specific words, not a difference in the underlying product.

Two different regulators, two different questions

The FTC (Federal Trade Commission) asks whether an advertising claim is truthful, substantiated, and not misleading — this applies to essentially any consumer product. The FDA (Food and Drug Administration) asks a narrower, more specific question: does a claim describe the product as intended to diagnose, treat, cure, mitigate, or prevent a disease, or to affect the structure or function of the body in a medical sense — because making that kind of claim reclassifies a product as a medical device, subject to an entirely different (and far more expensive and time-consuming) regulatory pathway than a general wellness product. A seller can violate either agency's rules independently, and a single poorly worded claim can trigger both at once.

The core distinction: physical effect versus medical outcome

"Produces localized warmth" describes a physical effect and is generally defensible when true. "Increases local blood circulation" starts to edge toward a physiological claim that typically requires substantiation beyond "customers say they feel warmer." "Relieves arthritis pain," "treats poor circulation," or "helps with [any named medical condition]" are disease claims — the kind of language that shifts a product's regulatory classification and is the single most common mistake sellers in this category make, often by translating marketing copy from another market's more permissive advertising standards without adapting it for the US regulatory context.

Why the "not a medical device" disclaimer is necessary but not sufficient

A disclaimer stating a product is not intended to diagnose, treat, cure, or prevent any disease is a standard and appropriate practice — but it does not retroactively fix specific claims made elsewhere in the same listing, packaging, or advertising that contradict it. A product page with a disclaimer in the fine print and a headline claiming it "treats chronic pain" does not resolve the conflict in the seller's favor; regulators and courts generally look at the overall net impression a reasonable consumer would take away, not just the disclaimer in isolation.

Where this risk actually shows up in practice

The highest-risk surfaces are usually not the ones a seller reviews most carefully: customer-facing marketplace listings written or translated by a third party, influencer or affiliate content the brand did not draft directly but is nonetheless associated with, and customer reviews or testimonials the brand chooses to feature or repost, which can carry disease claims a brand would never write itself but is still responsible for amplifying. A periodic audit of exactly what is live across every sales channel — not just the brand's own primary website — is worth treating as a real compliance task, not an afterthought.

How this connects to product descriptions and spec sheets

As covered in our far-infrared physics article, the responsible approach is describing a genuine physical mechanism (wavelength, penetration, thermal effect) accurately, without extending it into a specific medical outcome the product has not been evaluated for. The same discipline applies across every claim on a listing — negative ion output, thermal energy, or any other measurable spec should be described in physical terms, with any experiential language ("many users report feeling more relaxed") kept clearly separate from anything resembling a disease claim.

A practical review process before anything goes live

Before publishing a new listing, translated marketing copy, or an influencer brief, have someone read only the headline claims in isolation — stripped of context — and ask whether each one could be read as claiming to treat, cure, or prevent a specific named condition. If the honest answer is "it could be read that way," rewrite it before it goes live rather than after a complaint or a marketplace takedown notice arrives. This is a five-minute check that is dramatically cheaper than the alternative.