In July 2025, the U.S. FDA issued a warning letter to Whoop, Inc. for marketing its Blood Pressure Insights (BPI) feature without regulatory clearance. The agency concluded that Whoop’s sleep-based blood pressure estimation feature qualifies as a medical device, not a general wellness tool. This finding has implications far beyond one wearable band.

Whoop’s case highlights a growing issue in the digital health space: where exactly is the boundary between consumer wellness products and regulated medical devices? And what happens when that boundary is crossed?

Interested in Whoop vs Hilo review?

See the Quantified Scientist test of Whoop below.
Hilo band is a clinically proven device that measures your blood pressure at specific times without your intervention – somewhat similarly to Ambulatory Blood Pressure Monitoring but without cuff. It does not provide other features

What Did the FDA Say to Whoop?

According to the FDA, Whoop’s BPI function, which estimates systolic and diastolic blood pressure based on biometrics collected during sleep, is not “low risk” and is intended for medical purposes. Therefore, it cannot be marketed without appropriate FDA clearance. This runs contrary to Whoop’s claim that the feature is designed to support general wellness and self-awareness.

The agency made it clear: any feature that measures or interprets physiological parameters in a way that could be used for diagnosis, monitoring, or treatment falls squarely under the medical device category — regardless of disclaimers or marketing language.

Further analysis from industry sources confirms that the FDA is reinforcing a long-standing but often misunderstood principle: intended use is inferred not only from claims, but also from function and context. (Source: Mintz Legal Analysis)

It is worth noting, that user reviews claim that Whoop’s readings are often misleading, and it is no surprise as wrist measurement is much harder than on the upper arm cuff. However, FDA did not even discussed the reliability of the device. The case is that it did attempt to measure and monitor blood pressure at all.

Contrast with Aktiia’s Hilo Band

In stark contrast, Swiss MedTech company Aktiia pursued a fully regulated route for its cuffless blood pressure monitoring technology. The company’s flagship product marketed as the Hilo Band received 510(k) clearance from the FDA in July 2025. This made it the first-ever FDA-cleared wearable for over-the-counter cuffless blood pressure monitoring.

Unlike Whoop, Aktiia always positioned Hilo as a medical device. In Europe, it already holds a CE Mark under MDR as a Class IIa device, demonstrating compliance with EU Regulation 2017/745. It was developed in collaboration with clinicians, validated through peer-reviewed clinical trials, and built to meet regulatory requirements from day one.

Hilo’s strategy shows that it is possible to innovate in wearables while remaining on solid regulatory ground. That is if the product is clinically validated, and the claims are backed by science and cleared by regulators.

Regulatory Frameworks: EU MDR vs FDA

Under EU MDR (2017/745), any product that is intended to monitor or predict disease, or that provides data for diagnostic or therapeutic decisions qualifies as a medical device. This includes software, wearables, and connected apps. The CE-marking process requires clinical evaluation, conformity assessment, and continuous post-market surveillance.

Similarly, the FDA’s General Wellness Policy permits unregulated status only when features are demonstrably low-risk and not tied to medical decision-making. Estimating blood pressure, however, crosses that line.

Strategic Implications for MedTech and Digital Health

• Intended use drives classification. If a feature informs diagnosis, monitoring, or treatment, it likely requires regulatory clearance — even if branded as wellness.
• Claims matter. Disclaimers don’t override functionality. Regulators assess all available evidence: product labels, UI, marketing copy, and technical documentation.
• EU and US frameworks are converging. Compliance with EU MDR (Class IIa) strengthens your case for FDA clearance — and vice versa.
• Clinical validation is the foundation. Without it, wearable health features risk being blocked or recalled.

Final Thoughts: Whoop’s mistake

Whoop’s mistake wasn’t in innovating — it was in positioning a potentially diagnostic feature as a harmless wellness insight. That approach may work in fitness marketing, but not under the scrutiny of regulators.

By contrast, Aktiia’s Hilo Band shows how a regulated, evidence-based strategy enables long-term success across global markets. Its path — from CE mark in Europe to FDA clearance in the U.S. — should serve as a roadmap for future wearable startups operating in the cardiovascular or digital biomarker space.

As a European expert in medical device commercialization, I believe this moment is a wake-up call: marketing and regulatory must be aligned from day one. Otherwise, companies risk more than compliance failures — they risk losing consumer trust and market access.

Read more on Scaling MedTech: From Product to Market – disrupting.healthcare

Relevant Sources

• FDA Warning Letter to Whoop (July 2025)
• Aktiia’s Hilo Band FDA Clearance
• Legal Commentary from Mintz
• EU Medical Device Regulation 2017/745
• FDA General Wellness Policy

This content has been enhanced with GenAI tools.