FDA Warning Letter Breakdown: Testing the Line Between Consumer Wellness Claims and Regulated Physiologic Measurement Functions in Wearables
Inside the WHOOP vs. FDA story, where cuffless blood pressure insights are crashing into device regulation.
This breakdown is available for all subscribers. Only paid subscribers get regular full access to our breakdowns and other analyses. If you’re not already a paid subscriber, you can upgrade here. Want to stay out of our warning letter breakdowns? Contact us to access our global network of 3,250+ consultants and 250+ former FDA employees. We run audits, mock inspections, and remediation for 17 of the top 25 life science firms.
We have a different kind of breakdown today.
The FDA just issued a warning letter to WHOOP over its wrist‑based Blood Pressure Insights (BPI) feature, asserting the function is a regulated medical device (diagnosis‑implied) that is being marketed without marketing authorization—rendering it both adulterated and misbranded.
WHOOP has countered its that BPI is a wellness insight gated to its premium Life/MG tier and says the FDA is overreaching.
This is a line‑drawing moment for every digital health, wellness, and medtech platform outputting physiologic metrics that map to disease states. If you’re in this category it may be time to act. More specifically: inventory your claims, scrub UI signals, and align your evidence with an executable regulatory path.
Why this story matters for medtech
Blood pressure obviously isn’t just another “fun metric” to track with a wearable. It’s a core vital sign tied directly to hypertension, cardiovascular morbidity, and treatment decisions.
When a consumer wearable starts estimating systolic/diastolic values and presenting them in a way users could plausibly interpret clinically, FDA attention was inevitable.
The WHOOP action signals that the agency is ready to pierce wellness disclaimers when objective intent—claims, UI design, outputs, user behavior—points toward medical utility. That has sweeping implications for cuffless BP algorithms, AI‑derived vitals, longitudinal risk dashboards, and premium healthspan tiers across the wearables landscape.
What happened (a brief chronology)
Let’s walk through the sequence of events here:
May 8, 2025 – WHOOP announces BPI. In a blog post, WHOOP touts “daily systolic and diastolic blood pressure estimations” derived from overnight sensor data, calibrated by logging a traditional cuff reading, and framed as a way to understand links between blood pressure, sleep, stress, and performance. The post includes a bold disclaimer: “Blood Pressure Insights is not a medical device and cannot diagnose or manage medical conditions. It does not provide medical advice. Always consult your doctor for health concerns and never delay or modify medical care based on its information.”
May 15 & 27, 2025 – FDA/WHOOP discussions. WHOOP meets twice with CDRH to review the feature and argue that it falls under the healthy‑lifestyle software exclusion (FD&C Act §520(o)(1)(B)).
June 2, 2025 – WHOOP follow‑up letter to FDA. The company further explains functionality and rationale for non‑device status.
July 14, 2025 – FDA warning letter issued (posted July 15). The FDA determines BPI is a device; cites adulteration (§501(f)(1)(B)) and misbranding (§502(o)) for marketing without PMA/IDE or 510(k) notification; orders corrective action within 15 business days.
July 16, 2025 – CEO Will Ahmed pushes back publicly. In comments reported by the Boston Business Journal, Ahmed says the company is “not backing down” in the wake of the FDA’s action.
The FDA’s case in plain English
The FDA’s case boils down to five core arguments here. Let’s walk through each of them.
It’s a device (intended use). If you give users a blood pressure value (even an estimated range once per day), you’re in device territory because BP data are “inherently associated with the diagnosis of hypo‑ and hypertension.” The FDA is essentially saying you can’t wellness‑disclaimer your way out of §201(h).
As a device, it’s adulterated and misbranded. No approved PMA/IDE + no 510(k) premarket notification = adulteration (§501(f)(1)(B)) and misbranding (§502(o)). The FDA has not authorized BPI for any use.
Objective intent beats disclaimers. The FDA looked at WHOOP’s own words (“daily systolic and diastolic…,” “medical‑grade health & performance insights”), the BPI gauge’s green/yellow/orange banding, and user reports (monitoring hypertension) to infer diagnostic intent under 21 CFR 801.4. Disclaimers did not rescue the feature.
Comparability to cleared BP devices. The FDA cited prior clearances for noninvasive blood pressure measurement systems (product code DXN; 21 CFR 870.1130) to show it actively regulates similar outputs—even when labeling stops short of an explicit disease claim.
Risk rationale. Erroneous BP readings can delay treatment or falsely reassure patients, contributing to stroke, MI, heart failure, renal damage, cognitive decline, and premature death. High blood pressure remains a leading modifiable risk factor; it's not “low risk,” so it’s outside the FDA’s General Wellness policy.
What WHOOP says it’s doing
WHOOP’s launch materials position BPI as “groundbreaking” but beta, gated to the premium Whoop Life membership and MG hardware.
Users must input cuff readings to calibrate. Estimates are generated once per morning from overnight PPG/HR/HRV signals, and long-term trends are available in the app. Company messaging emphasizes wellness, performance, and “deeper understanding” over diagnosis.
Again, post‑warning-letter, CEO Will Ahmed told followers (per Boston Business Journal) the company is “not backing down.” While details are sparse, we might expect an aggressive defense framing BPI as a lifestyle insight analogous to heart rate variability—another metric that straddled wellness/clinical use in its early consumer wearables days.
WHOOP has cleared tech before
For a little interesting regulatory context here, WHOOP isn’t new to market clearance via the FDA. It successfully obtained 510(k) clearance (K243236; SE April 4, 2025) for its over‑the‑counter ECG software feature, demonstrating the company can navigate FDA pathways when it chooses to.
That cleared predicate may influence FDA expectations that WHOOP understands device obligations, and raise the bar for any argument that BPI was an innocent wellness experiment.
Reading the tea leaves: 5 takeaways for industry
Let’s make this a “teachable moment” for anyone planning to bring wearable tech to market that challenges the regulatory line.
Metrics that map to diagnoses will receive high scrutiny. It really doesn’t pay to kid yourself here. If your algorithm outputs a value that clinicians routinely use to diagnose, stage, or manage disease (BP, SpO₂, glucose proxies, arrhythmia flags), it’s best to assume FDA authority unless you’ve affirmatively de‑risked scope with the agency. WHOOP’s disclaimer didn’t matter.
UI and color coding convey intended use. This one’s not as obvious but fascinating and just as important. Green/yellow/red (or similar) bands, trend arrows, or “in‑range” language will be read as clinical signaling—even if the copy says “for wellness only.” Audit for visual intent, not just text. Also, consider surrogate names (e.g., “vascular load index”) only if backed by data and not misleading. Remember: the FDA can still infer intent.
“Feature-gating” doesn’t shield you. Placing medically adjacent functions behind premium tiers (Whoop Life) or hardware variants (MG) does not avoid device regulation if the function itself meets the definition. The FDA evaluated the marketed feature set, not the price wall. Don’t plan on paywalling yourself into a medical device.
Bring the evidence or back off. WHOOP references training on >11k users / 32k sleep sessions and cuff calibration, but has not (publicly) shown performance against recognized BP standards (e.g., ISO 81060 series; IEEE cuffless BP). If you can’t meet performance expectations, reconsider public launch or narrow your claims. Make sure you align your data capture with recognized performance standards early.
Regulator memory is pretty long. Once you’ve interacted with the FDA (WHOOP did—twice—before launch escalation), the agency will expect responsiveness. A decision to proceed anyway may heighten enforcement tone, as seen here.
Also, if applicable, be sure to limit beta exposure or restrict to IRB‑approved research cohorts when evidence is immature. WHOOP labeled BPI beta, but still broadly marketed.
Final thought
Regulators are increasingly skeptical of the “it’s just a wellness insight” defense when software infers medically meaningful numbers from consumer sensors. WHOOP is the current flashpoint. Use this moment to revisit your own risk posture before your product becomes the next enforcement headline.
Need audit, mock inspection, remediation, or warning letter/483 response support? Let’s talk.
Contact us to access our exclusive pool of over 3,250 global consultants, including 250 former FDA officials. If we haven't yet partnered on project support, we provide end-to-end audit support and intensive, comprehensive mock FDA inspections that not only mirror real inspections but also delve deeper, providing the insights, corrections, and readiness you need before the FDA visits your facility.
With a staff of thousands of resources worldwide, we're the partner firms work with when they want deep domain expertise and the peace of mind that comes with a partner whose commitment to quality and integrity reflects their own.
Whether you need a complete audit program design, full execution, or specific audit support, we're here to help. Drop us a line to start the conversation.
Who is The FDA Group?
The FDA Group helps life science organizations rapidly access the industry's best consultants, contractors, and candidates. Our resources assist in every stage of the product lifecycle, from clinical development to commercialization, with a focus on Quality Assurance, Regulatory Affairs, and Clinical Operations.
With thousands of resources worldwide, hundreds of whom are former FDA, we meet your precise resourcing needs through a fast, convenient talent selection process supported by a Total Quality Guarantee. Learn more and schedule a call with us to see if we’re a fit to help you access specialized professionals and execute your projects on time and on budget.