Whoop There It Is: FDA Warning Letter Now Anchors a Class Action Against Whoop

The plaintiff consumer invokes the FDA’s position to claim that the feature renders the product an unauthorized medical device and that Whoop’s promotion of it as part of a premium paid membership service was unlawful. The plaintiff seeks monetary damages on the theory that consumers paid more for features that were not legally marketed and asks the court to halt further promotion of the blood-pressure functionality.

When a feature falls within a category that the FDA has long and actively regulated, wellness branding and disclaimers will not sidestep device requirements. Companies are better served assuming device status from the outset, defining a precise intended use, engaging the FDA early, and preparing the appropriate premarket submission. This posture reduces the risk of enforcement and follow‑on consumer litigation while preserving a credible path to market.

The case is Rowe v. Whoop, Inc., No. 3:25-cv-09910 (N.D. Cal. Nov. 18, 2025).

The Lawsuit in Brief

Whoop is a wrist-based wearable and analytics platform focused on sleep, cardiovascular metrics, strain, and recovery. The WHOOP MG is the company’s latest device — an upgraded hardware generation that supports new signal-processing capabilities and expanded analytics. The MG is available only with the purchase of a WHOOP Life membership, or Whoop’s top-tier membership offering that unlocks additional insights, specialized analytics modules, and certain performance and coaching features on top of the standard subscription. Notably, the MG and Life membership include access to a daily “Blood Pressure Insights” (BPI) feature that displays estimated systolic and diastolic ranges on a color‑coded gauge in the companion WHOOP application.

In the Rowe lawsuit, a California consumer alleges that Whoop promoted its MG device and Life membership with “medical‑grade” claims. The complaint ties these representations to the premium price that Whoop charged for the Life membership tier and asserts that consumers were misled about both the BPI’s capability and legality. Anchoring its theory in the FDA’s July 2025 warning letter, the complaint alleges that the BPI feature renders the product a medical device sold without the required premarket authorization or notification, causing the product to be adulterated and misbranded under federal law and therefore unable to be lawfully sold in California.

The pleading advances claims under California’s Unfair Competition Law, False Advertising Law, and Consumer Legal Remedies Act, along with an unjust enrichment claim. It seeks restitution, damages, injunctive relief, and attorneys’ fees. While the case remains at an early stage and the allegations are unproven, the regulatory hook is significant because it links a theory of unlawful deception to the FDA’s stated position and, in doing so, raises litigation risk for other wearable companies making similar claims without clearance.

FDA’s View of Blood Pressure Features and the Wellness Exception

The FDA’s warning letter concludes that Whoop’s BPI feature is a medical device based on intended use as evidenced by its design, outputs, and marketing. The agency focused on Whoop’s own descriptions of daily systolic and diastolic estimations and on the user interface that presents results on a gauge with colored target zones. In the FDA’s view, any function that measures or estimates blood pressure is inherently associated with diagnosing hypertension and hypotension and is therefore intended for the diagnosis, cure, mitigation, treatment, or prevention of disease. On that basis, the FDA deemed the product adulterated for lack of appropriate premarket authorization and misbranded for lack of premarket notification.

The Federal Food, Drug, and Cosmetic Act provides that a software function is not a device if it is intended for maintaining or encouraging a healthy lifestyle and is unrelated to the diagnosis, cure, mitigation, prevention, or treatment of a disease or condition. This is often referred to as the “wellness exception.” Risk is central to the analysis and to the limits of the wellness exception, which the FDA interprets to apply only to low‑risk functions that are unrelated to disease diagnosis or treatment. In its letter to Whoop, the FDA concludes that the wellness exception does not apply to the BPI feature, explaining that blood‑pressure estimation is not low risk because inaccurate outputs can cause harm by falsely reassuring hypertensive users or delaying care for a condition that often lacks symptoms. The agency also points to real‑world clinical practice, where home and ambulatory blood‑pressure monitoring are standard, and to its long‑standing active regulation of blood‑pressure measurement devices.

Under the FDA’s intended‑use framework, a product’s purpose is determined by the totality of the evidence. The agency infers objective intent from the feature’s design and outputs, its labeling and marketing, and how a reasonable user would interpret the interface. Disclaimers and wellness framing do not override such evidence. In the context of blood pressure features, numeric estimates are treated as blood‑pressure measurements, and interface elements that tie results to sleep, recovery, or performance can further signal disease‑related intent. Broader market trends reinforce this view. As a prominent example, Apple obtained 510(k) clearance for a Hypertension Notification Feature available on select models of the Apple Watch that detects patterns suggestive of possible high blood pressure.

Following the warning letter, Whoop publicly stated that it disagrees with the FDA’s characterization of the BPI feature and maintains that it is not intended for diagnosis or treatment. As of now, Whoop has not recalled any of the MG products, and the BPI functionality remains accessible to users with an MG wearable and Life membership.

Practical Implications: Product, Marketing, and Litigation Risk

With wearable innovations advancing rapidly amid consumer expectations for deeper physiological insights and understandable pressure to reach the market quickly, moving ahead without alignment with the FDA’s requirements can be counterproductive, inviting delays, rework, and enforcement action. The Rowe lawsuit further illustrates that FDA enforcement risk may expose a business to downstream consumer protection claims.

Taking all these considerations into account, companies developing blood‑pressure‑related functionality for wearables should:

• Assume device status and plan for an appropriate premarket pathway supported by clinical validation, risk controls, and early engagement with the FDA.
• Align product design, labeling, and marketing with the validated intended use.
• Not rely on disclaimers to reframe disease‑related outputs as “wellness” features.
• Expect that FDA enforcement will catalyze private litigation premised on claims of unlawful marketing and price inflation.
• Calibrate consumer messaging to match the substantiation and regulatory status of the product.

Durable commercialization will favor companies that right‑size claims, keep user interfaces within cleared indications, and sequence regulatory milestones with launch plans.

ArentFox Schiff supports clients across these dimensions — from intended-use scoping and FDA engagement to evidence strategy, labeling review, and litigation-risk assessment — to help innovators in the wearables, digital health, and longevity sectors move quickly while managing regulatory and consumer-litigation exposure.