WARNING LETTER

WHOOP, Inc. MARCS-CMS 709755 — July 14, 2025

Delivery Method:: VIA Electronic Mail
Product:: Medical Devices

Recipient:: Recipient Name

Will Ahmed; Recipient Title

Chief Executive Officer; WHOOP, Inc.; One Kenmore Sq. Suite 601
Boston, MA 02215
United States

Issuing Office:: Center for Devices and Radiological Health; United States

WARNING LETTER

CMS # 709755

July 14, 2025

Dear Will Ahmed:

The United States Food and Drug Administration (FDA) has learned that your firm is marketing Blood Pressure Insights (hereinafter, "BPI") in the United States without marketing clearance or approval, in violation of the Federal Food, Drug, and Cosmetic Act (The Act). Under section 201(h) of the Act, 21 U.S.C. § 321(h), this product is a device because it is intended for use in the diagnosis of disease or other conditions or in the cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body.

FDA has reviewed your firm's website, www.whoop.com/us/en/ (last reviewed May 28, 2025), your associated article "WHOOP Delivers Innovative Blood Pressure Insights for a Deeper Look at Your Well-Being" (last reviewed May 28, 2025), and your firm's responses to previous FDA inquiries regarding BPI (detailed below). Based on our review of these materials, your firm offers BPI to users and intends for those users to measure or estimate their blood pressure. Your website describes the product as providing "daily systolic and diastolic blood pressure estimations, offering members a new way to understand how blood pressure affects their performance and well-being." Your website further lists BPI as an example of how WHOOP is "delivering medical-grade health & performance insights." The associated article clarifies that "the impact of blood pressure on sleep, recovery, and performance are not well understood or widely studied."

FDA has determined that BPI is adulterated under section 501(f)(1)(B) of the Act, 21 U.S.C. § 351(f)(1)(B), because your firm does not have an approved application for premarket approval (PMA) in effect pursuant to section 515(a) of the Act, 21 U.S.C. § 360e(a), or an approved application for an investigational device exemption under section 520(g) of the Act, 21 U.S.C. § 360j(g). The device is also misbranded under section 502(o) of the Act, 21 U.S.C. § 352(o), because your firm did not notify the agency of its intent to introduce the device into commercial distribution, as required by section 510(k) of the Act, 21 U.S.C. § 360(k). For a device requiring premarket approval, the notification required by section 510(k) is deemed satisfied when a PMA is pending before the agency. (see 21 CFR 807.81(b)) The kind of information that your firm needs to submit in order to obtain approval or clearance for the device is described at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/how-study-and-market-your-device. FDA will evaluate the information that your firm submits and decide whether the product may be legally marketed.

FDA has not authorized BPI for any use, including for the measurement or estimation of a user's blood pressure.

Your firm met with representatives of FDA's Center for Devices and Radiological Health (CDRH) on May 15, 2025, and May 27, 2025, to discuss BPI. Your firm sent a letter dated June 2, 2025, to describe the purpose of the BPI feature, how it works, and why you believe it is not a medical device subject to FDA regulatory authority. In these calls and this letter, your firm represented that it was indeed marketing BPI without any marketing authorization from FDA and that when used, it would provide a user with a daily estimation of their blood pressure. Your firm indicated that you believe that BPI is not a device under section 201(h) of the Act because you believe it is not intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease. Your firm also indicated that you believe that BPI falls under section 520(o)(1)(B) of the Act, which excludes from the definition of "device" software functions that are intended for maintaining or encouraging a healthy lifestyle that are unrelated to the diagnosis, cure, mitigation, prevention, or treatment of a disease or condition.

An article's intended use is based on the objective intent of the persons responsible for its labeling, and may be shown by the person's expressions, the design or composition of the article, or the circumstances surrounding its distribution (21 CFR 801.4). Based on FDA's evaluation of BPI's intended use, the product is intended to provide a measurement or estimation of a user's blood pressure, which is inherently associated with the diagnosis of hypo- and hypertension, and is therefore intended for use in the diagnosis of a disease or other condition, or in the cure, mitigation, treatment, or prevention of disease. This conclusion is bolstered by both your firm's statements about BPI (e.g., "Higher blood pressure may be an indicator of poor sleep." [emphasis added]) and BPI's design, which outputs a blood pressure measurement to users and provides the reading on a gauge that uses green, yellow, and orange color-coding to indicate a target blood pressure range. Our conclusion is consistent with prior FDA actions, as FDA has reviewed and cleared as a medical device other blood pressure measurement products intended to provide a measurement or estimation of a user's blood pressure without explicit reference to diagnosis of hypo- or hypertension in their labeling or otherwise (e.g., devices authorized within product code DXN), because of the measurement's inherent association with those conditions.¹ BPI has the same intended use as those devices—i.e., to provide blood pressure measurement.

This understanding of a blood pressure measurement device's intended use is also supported by FDA's classification regulations, which do not include explicit references to diagnosis of hypo-or hypertension (e.g., 21 CFR 870.1130). Although BPI provides a daily blood pressure range and midpoint measurement instead of a real-time reading, that is not sufficient to distinguish the product's intended use from other blood pressure measurement devices, because a blood pressure range or midpoint estimation, like a real-time reading, is inherently associated with the diagnosis of hypo- and hypertension.² Even accounting for BPI's disclaimers, they do not change this conclusion, because they are insufficient to outweigh the fact that the product is, by design, intended to provide a blood pressure estimation that is inherently associated with the diagnosis of a disease or condition. The inefficacy of such disclaimers is demonstrated by evidence of individuals using BPI to monitor their hypertension.

Per section 520(o)(1)(B) of the Act, 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. BPI is not intended to "maintain" or "encourage" a healthy lifestyle, as it implies a causal link between a user's blood pressure measurement and wellness results. For example, BPI and its labeling would indicate to a user that her poor sleep may be caused by high blood pressure identified by the device. Further, as noted above, BPI is not unrelated to the diagnosis, cure, mitigation, prevention, or treatment of a disease or condition, because it is inherently associated with the diagnosis of hypo- and hypertension, and because your firm's statements indicate that BPI is intended to identify "higher blood pressure."

Even if the product's intended use related solely to sustaining or offering general improvement to functions associated with a general state of health while referring to diseases or conditions (see FDA's guidance "General Wellness: Policy for Low Risk Devices" category two, pages 4-5), this product would not be considered low risk, and therefore would not be within the general wellness policy. Providing blood pressure estimation is not a low-risk function. High blood pressure is the most prevalent modifiable risk factor for cardiovascular disease in this country. Although traditionally blood pressure has been checked in a healthcare setting, ambulatory blood pressure checks are now in the American Heart Association (AHA) guidelines (2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines), and individuals are encouraged to check their own blood pressure at home. An erroneously low or high blood pressure reading can have significant consequences for the user. For example, if an individual with hypertension used a device that resulted in falsely low blood pressure measurements, those results could lead to inappropriate reassurance that they have a normal blood pressure. This could be compounded by elevated blood pressure measurements at their doctor's office which may be misinterpreted as white coat hypertension. This can result in a delay or even a lack of treatment, which can result in serious impacts to that patient's cardiovascular health and end organ damage. These include stroke, heart attack, heart failure, kidney failure, cognitive decline, and premature death. Inaccurate or imprecise measurements are especially concerning for a disease like hypertension because it often presents without physical symptoms. The guidance further states that "In assessing whether a product is low risk for purposes of this guidance, FDA recommends that you also consider whether CDRH actively regulates products of the same type as the product in question." FDA actively regulates devices intended to measure or estimate a user's blood pressure (see 21 CFR 870.1130).

At the conclusion of your firm's calls with FDA, your firm indicated its intention to continue marketing BPI without appropriate FDA authorization despite FDA's repeated assertions that BPI is a medical device and therefore requires FDA authorization to be legally marketed.

Your firm should take prompt action to address any violations identified in this letter. Failure to adequately address this matter may result in regulatory action being initiated by the FDA without further notice. These actions include, but are not limited to, seizure, injunction, and civil money penalties.

Other federal agencies may take your compliance with the FD&C Act and its implementing regulations into account when considering the award of federal contracts.

Please notify this office in writing within fifteen business days from the date you receive this letter of the specific steps your firm has taken to address the noted violations, as well as an explanation of how your firm plans to prevent these violations, or similar violations, from occurring again. Include documentation of the corrections and/or corrective actions (which must address systemic problems) that your firm has taken. If your firm's planned corrections and/or corrective actions will occur over time, please include a timetable for implementation of those activities. If corrections and/or corrective actions cannot be completed within fifteen business days, state the reason for the delay and the time within which these activities will be completed. Your firm's response should be comprehensive and address any violations included in this Warning Letter. If you believe that your products are not in violation of the FD&C Act, include your reasoning and any supporting information for our consideration as part of your response.

Your firm's response should be sent via email to Hetal Odobasic at CDRHEnforcementfda.hhs.gov. Please include in the subject line, "CMS Case 709755" when replying. If you have any questions about the contents of this letter, please contact: LCDR Stephen Browning at stephen.browning@fda.hhs.gov.

Finally, you should know that this letter is not intended to be an all-inclusive list of the violations at your firm. It is your firm's responsibility to ensure compliance with the applicable laws and regulations administered by FDA.

Sincerely,
/S/

Angela C. Krueger
Deputy Director for Regulatory Policy
Office of Product Evaluation and Quality
Center for Devices and Radiological Health
Food and Drug Administration

CC:

James Yeagle, Associate General Counsel (b)(6)@whoop.com
Jonathan Jeffrey, Chief of Staff to the CEO, jonathan@whoop.com

______________________

1 "High blood pressure, also called hypertension, is blood pressure that is higher than normal." https://www.cdc.gov/high-blood-pressure/about/index.html. See also "ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines," https://www.ahajournals.org/doi/10.1161/hyp.0000000000000065.

2 Indeed, it is common for blood pressure measurement devices to supply a range associated with the device's reading, either in labeling or through the device itself. These outputs also typically represent an estimate of blood pressure with inherent uncertainty to account for variability demonstrated in clinical validation studies, as described in the labeling for devices authorized under product code DXN.