Not FDA’s Whoop-ing Boy: How a Warning Letter Became a Wellness Playbook

The 12-month arc between those two letters is one of the most instructive sequences in recent wearable health regulation: the FDA abandoned its initial enforcement theory, overhauled its General Wellness guidance, and Whoop modified its product to align with the new framework. 

Today, Whoop is not only marketing the feature but has been selected for the Centers for Medicare & Medicaid Services’ (CMS) Advancing Chronic Care with Effective, Scalable Solutions (ACCESS) program to bring wearable-enabled care to Medicare beneficiaries managing chronic conditions and holds a contract to support the US Navy’s readiness monitoring program. The outcome is a case study in the payoff of persistent, constructive engagement with regulators, even when the starting positions are far apart. Now that the enforcement action, the guidance revision, and Whoop’s subsequent federal partnerships have all landed, the full picture is in view. It offers the clearest look yet at how the FDA now draws the line between wellness and device territory.

The FDA’s Pivot

The 2025 Warning Letter rested on what many in the industry viewed as an aggressive theory by the government: that blood pressure measurement is “inherently associated” with diagnosing hypertension, and therefore any product that estimates blood pressure is a medical device, regardless of labeling or marketing. That theory, if it held, would have made it virtually impossible for wearables to offer blood pressure features without premarket clearance.

Spoiler: It did not hold. On January 6, the FDA issued a substantially revised General Wellness: Policy for Low Risk Devices guidance that abandoned the “inherently associated” framework entirely. Under the updated guidance, noninvasive products that estimate physiologic parameters, including blood pressure, oxygen saturation, blood glucose, and heart rate variability, can qualify as general wellness products. The question is no longer what a product measures — it is whether the total product experience positions the measurement as wellness or as clinical. That standard will govern how an entire generation of next-frontier wearables and consumer health technologies is classified, from noninvasive continuous blood glucose monitors to EEG-based wearable neurotech now entering the market. 

Whoop worked with the FDA and made modifications to its product and labeling to align with the updated framework. On June 17, the FDA issued a closeout letter stating that, based on those modifications and “consistent with” the updated guidance, the agency does not intend to enforce device requirements on the modified feature.

What the Warning Letter, Guidance, and Closeout Letter Tell Us Together

The arc from Warning Letter to closeout, with a major guidance revision in between, is the clearest picture we have had of how the FDA now evaluates wellness wearables. Here is what the framework actually looks like.

The FDA has moved from policing the measurement to policing the experience. The 2025 Warning Letter said blood pressure estimation was categorically clinical. The 2026 guidance says it does not have to be. What matters now is the total product experience: labeling, marketing copy, user interface design, notifications, subscription packaging, and how features are positioned relative to one another. The FDA evaluates intended use objectively, based on the full record, not just what a company claims (or disclaims) its product is for. Notably, these factors carry weight beyond FDA classification and map closely onto the framework the Federal Trade Commission and state attorneys general apply to unfair or deceptive trade practices claims. Practically speaking, this means that the same product experience that draws FDA scrutiny could simultaneously invite consumer protection enforcement and private litigation.

Your user interface (UI) is a regulatory document. The Warning Letter specifically cited a green/yellow/orange color-coded gauge as evidence of diagnostic intent because it mimicked clinical threshold displays. Under the 2026 guidance, products may display values, ranges, trends, and longitudinal summaries, but they cannot include “values that mimic those used clinically unless validated” or reference clinical thresholds. The guidance permits contextualizing outputs in relation to sleep, recovery, or similar wellness domains. Notably, Whoop’s modification was not to eliminate color-coding entirely but to shift from distinct color-blocked categories to a continuous color gradient. That is an interesting design distinction: discrete color zones imply defined cutoffs (normal, elevated, high), while a gradient conveys relative positioning without categorical judgment. The FDA accepted the gradient approach as consistent with wellness use. But companies should tread carefully. The line between wellness visualization and clinical signaling is not well defined in the guidance, and the closer a display resembles clinical convention, the greater the risk.

Words like “medical-grade” are now a bright-line disqualifier. The 2026 guidance explicitly prohibits claims of “clinical equivalence, clinical accuracy, or medical grade.” The Warning Letter flagged exactly this language. For companies seeking the wellness pathway and drafting marketing copy, this one is simple: do not use those words — do not even imply them.

How you bundle and tier subscription features signals intended use. Whoop’s blood pressure feature sat in the same subscription tier as its FDA-cleared ECG feature — product positioning that suggests these features belong in the same regulatory category. The 2026 guidance says products cannot be “intended to substitute for an FDA-authorized, cleared, or approved device.” Subscription architecture is now part of the intended-use analysis.

The notification paradox is real and unresolved. The 2026 guidance permits products to notify users that “evaluation by a healthcare professional may be helpful,” but such notifications cannot name a disease, characterize an output as “abnormal,” or include clinical thresholds. How to define a “range appropriate for general wellness use” for blood pressure that is meaningfully different from a clinical threshold is an open question the FDA has not yet answered. Companies in this space will need to navigate that ambiguity carefully.

Key Takeaways

The 2026 guidance gives wearable and consumer health companies a real pathway to market advanced biometric features without premarket clearance. But a guidance document is a starting point, not a finished regulatory framework. The open questions flagged above will be resolved product by product, as companies put novel designs in front of the agency and the FDA evaluates them against a framework it is still pressure-testing. The stakes of those case-by-case resolutions are heightened by a deeper market tension: longevity-minded consumers increasingly expect clinical-grade performance from their wearables, and these platforms are rapidly becoming integrated entry points for care delivery, connecting users to telehealth, payor-sponsored programs, and chronic disease management. 

Every FDA submission, every pre-submission meeting, and every enforcement action will refine where the lines are. Whoop’s experience shows both the cost of misalignment and the value of staying at the table: the company engaged with the FDA through the Warning Letter process, modified its product, and came out the other side with a resolved enforcement action, a CMS partnership, and a federal defense contract. Before launching or updating any feature that touches physiologic parameters, review the full product experience, from labeling and user interface to marketing, notifications, and subscription structure, as a single regulatory package. The question to ask is whether the total experience reads as wellness or as medicine. The FDA will be looking at the same thing.

If you are interested in learning more about or seeking guidance on the FDA’s regulation of wearables, wellness products, or anything in between, please contact the authors.