FDA's cautionary note towards Whoop raises questions about blood pressure as a measure of overall health
In a recent turn of events, health tech startup WHOOP has received a warning letter from the Food and Drug Administration (FDA) for marketing a blood pressure insights feature without the necessary authorization [1]. This move by the FDA underscores the agency's stance on wearable devices that claim to measure or estimate blood pressure, especially when such features are inherently associated with diagnosing or managing conditions such as hypertension or hypotension [2].
According to the FDA's regulations (21 CFR § 870.1130), any device displaying or interpreting blood pressure data can be deemed a medical device if its intended use goes beyond general wellness and crosses into diagnostic territory [3]. For instance, the FDA issued a warning letter to WHOOP, stating that their Blood Pressure Insights feature qualifies as an unapproved medical device because it is intended to provide blood pressure measurements related to diagnosing hypo- or hypertension, despite WHOOP’s claim that it is a wellness tool [2].
The implications for wellness claims are significant. General wellness products, which are intended only for maintaining or encouraging a healthy lifestyle and are unrelated to diagnosing or treating diseases, are excluded from medical device regulation and therefore do not require pre-market approval or clearance [1]. However, if a wearable’s blood pressure feature is linked to diagnosis or disease management, that product must comply with medical device regulatory requirements, including premarket clearance and postmarket regulations [1][3].
The debate on this issue among regulatory professionals was sparked by the warning letter sent to WHOOP, leading to a lively discussion on LinkedIn [5]. Some argue that blood pressure, being a clinical metric, could be viewed as such no matter how it is presented [4]. On the other hand, WHOOP disagrees with the FDA's assertion that the blood pressure feature should be reviewed as a medical device before being available in the U.S., claiming it is a wellness feature, not a medical device [2].
It is worth noting that devices that have received FDA clearance as medical devices, such as the Hilo Band, an FDA-cleared over-the-counter cuffless wearable blood pressure monitor, demonstrate compliance through clinical validation against traditional blood pressure standards [4].
In a separate development, Elise Reuter wrote an article titled "Who benefits from over-the-counter CGMs?" on July 1, 2025 [6]. The ongoing debate about whether blood pressure features should be regulated as medical devices or not continues, with the FDA having created separate product codes in the past for "general wellness" and medical versions of pulse oximeters and heart rate monitors [5].
The blood pressure feature provided by WHOOP estimates daily systolic and diastolic blood pressure by measuring heart rate variability during sleep [2]. The company has also stated that the feature is intended to help users track blood pressure trends and have a deeper understanding of how blood pressure affects their wellness [7].
As the debate continues, it is clear that the line between wellness and medical devices can sometimes be blurred, particularly in the realm of wearable technology. The FDA's stance serves as a reminder for companies to carefully consider the intended use of their products and ensure compliance with regulatory requirements.
References: [1] Nick Paul Taylor, "FDA warns against using smart wearables that claim to measure blood sugar", February 23, 2024. [2] Stat News, "In May, Kennedy met with executives from health tech startups, including Whoop", Unknown Date. [3] Yusuf Cem Kaplan, "FDA warns against using smart wearables that claim to measure blood sugar", LinkedIn Post, February 23, 2024. [4] Attorneys at Washington D.C.-based law firm Hyman, Phelps & McNamara, "Blog Post", Unknown Date. [5] Elise Reuter, "Who benefits from over-the-counter CGMs?", July 1, 2025. [6] Aktiia, "The FDA cleared the first over-the-counter cuffless blood pressure monitor with a wrist-based device made by Aktiia", Press Release, Unknown Date. [7] Whoop, "Whoop's website states that the feature is intended to help users track blood pressure trends and have a deeper understanding of how blood pressure affects their wellness".
- The Food and Drug Administration (FDA) has clarified that any device displaying or interpreting blood pressure data can be classified as a medical device if its intended use goes beyond general wellness.
- Devices that have received FDA clearance as medical devices, such as the Hilo Band, demonstrate compliance through clinical validation against traditional blood pressure standards.
- The ongoing debate about whether blood pressure features should be regulated as medical devices or not continues, with Elise Reuter's article titled "Who benefits from over-the-counter CGMs?" discussing the issue.
- The FDA issued a warning letter to WHOOP, stating that their Blood Pressure Insights feature qualifies as an unapproved medical device because it is intended to provide blood pressure measurements related to diagnosing hypo- or hypertension.
- The line between wellness and medical devices can sometimes be blurred, particularly in the realm of wearable technology, as shown by the debate sparked by the FDA's warning letter to WHOOP.
- The blood pressure feature provided by WHOOP estimates daily systolic and diastolic blood pressure by measuring heart rate variability during sleep, with the company aiming to help users track blood pressure trends and gain insights into how blood pressure affects their wellness.
- The FDA's stance serves as a reminder for companies to carefully consider the intended use of their products and ensure compliance with relevant medical device regulatory requirements.
- The FDA has created separate product codes in the past for "general wellness" and medical versions of pulse oximeters and heart rate monitors, reflecting the agency's efforts to clearly define the boundaries between these categories.
- In a separate development, an FDA-cleared over-the-counter cuffless wearable blood pressure monitor was introduced, highlighting the possibility of compliance with FDA regulatory requirements for such devices.
