Oura faces class action lawsuit over sleep tracking accuracy claims

Oura, the Finnish company known for its popular smart ring that tracks health, fitness, and sleep, is facing a proposed class action lawsuit alleging it falsely advertised the accuracy of its sleep tracking. The lawsuit, filed by Clarkson Law Firm in San Francisco on behalf of Madison Surber, a Californian who purchased an Oura Ring in 2025, claims that the device cannot accurately measure sleep stages.

The complaint argues that Oura's marketing claims, including a "79%" accuracy in sleep-stage tracking and more recently "95% Sleep Staging Accuracy compared to clinical sleep lab," are unsubstantiated because the ring lacks the sensors needed to directly measure brain activity and eye movements that define sleep stages. According to the lawsuit, accurate sleep staging requires equipment such as scalp electrodes and eye sensors used in clinical polysomnography, the gold-standard sleep study.

The lawsuit quotes Oura's marketing as saying its rings are "built for accuracy" and capable of providing "unparalleled accuracy" in tracking sleep stages—wake, light, deep, and REM sleep. The complaint reads, "To capitalize on consumers' desire for a tracker that could actually track sleep and monitor their sleep cycles, Oura sold expensive tracking rings, priced at $300 and up, advertising exactly that: that Oura rings are capable of seeing what only a hospital sleep lab can see."

The lawsuit describes Oura's sleep stages as "AI-generated guesses" with roughly "a coin flip's chance" of being right, according to a press release from Clarkson Law Firm. The filing cites a study of 45 patients that found overall sleep stage classification accuracy of 53.18%, with REM sleep overestimated by an average of 31.56 minutes.

The case names Oura Inc. and its Finnish parent Oura Health Oy as defendants. It carries seven counts, including fraud by misrepresentation and breaches of California's Unfair Competition Law and False Advertising Law. Alongside damages, it asks for a corrective advertising injunction requiring prominent disclaimers.

Oura's response

Oura has disputed the allegations. In a blog post titled "Standing Behind Our Science," the company wrote, "A recent baseless, opportunistic legal allegation seeks to discredit how consumer wearables—including Oura Ring—track and estimate sleep stages. We dispute these allegations and stand firmly behind our research and accuracy."

A spokesperson for Oura reaffirmed this stance, stating, "We stand behind our science, research, and accuracy claims," and adding that its sleep staging has been compared favorably against polysomnography in multiple studies. Oura says it estimates sleep stages using heart rate, heart rate variability, movement, breathing, and temperature data, citing peer-reviewed evidence.

The debate over wearable accuracy

The lawsuit raises broader questions about the reliability of wearable sleep tracking. Lifehacker's coverage notes that the Oura Ring contains red and green (and infrared) LEDs, motion sensors, and a temperature sensor, and calculates respiration rate and heart rate variability from heartbeat fluctuations. It also points to a 2024 study comparing the Oura Ring Gen 3, Fitbit Sense 2, and Apple Watch Series 8, which found a sensitivity of 75% or better for detecting sleep stages—a result one author of the study, who is also a consultant for Oura, highlighted.

Lifehacker's article expresses skepticism, noting that while the study results are notable, "I don't find the results particularly impressive" and suggests that "we should not put too much stock in any wearable's claims." The same article emphasizes that the case has not gone to trial and no judgment has been made, and notes that many lawsuits end in private settlements.

The Next Web's coverage highlights the timing of the lawsuit relative to Oura's confidential IPO filing in May, after reaching an $11 billion valuation that made it Europe's most valuable consumer health hardware company. The article also notes European legal context, including the Unfair Commercial Practices Directive and the Representative Actions Directive, which could have implications.

Oura launched in 2015 and has sold 5.5 million rings, up from 2.5 million as of June 2024, with revenue around $1 billion. The company filed a draft IPO with the SEC earlier this year.

Perspectives

Clarkson Law Firm (plaintiff's counsel): The lawsuit alleges that Oura's sleep tracking is based on AI-generated guesses with no more reliability than a coin flip, and that the company's marketing claims are false and misleading.

Oura: The company disputes the allegations, calling them baseless and opportunistic, and stands behind its science, research, and accuracy claims, citing peer-reviewed evidence and comparisons against polysomnography.