Smart ring maker Oura faces lawsuit over inaccurate sleep-tracking claims

“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, including the four different stages of sleep,” the complaint reads. “Oura did not just claim to measure a heartbeat or a temperature, but the exact stage of sleep the wearer is in—which in reality requires electrodes in the scalp and sensors on the eyes, as only a hospital or other clinical setting can do.”

It says the company has claimed “79%” accuracy in sleep-stage tracking and, more recently, “95% Sleep Staging Accuracy compared to clinical sleep lab.”

Attorneys brought the suit on behalf of Madison Surber, a Californian who purchased an Oura Ring for $513.68 in 2025 based on the disputed marketing claims.

“Sleep happens in the brain, not on one’s finger,” the complaint states.

Oura’s smart ring has evolved beyond sleep tracking to offer a broader range of health and wellness features. (Image credit: Nandagopal Rajan/Indian Express)

Oura disputes the allegations.

“We dispute the allegations and will defend against them in the appropriate legal forum,” the company said in a statement to indianexpress.com

“Oura Ring estimates sleep stages using multiple physiological signals, including heart rate, heart rate variability, movement, breathing patterns, and temperature,” the company said. “There is well-documented, peer-reviewed independent scientific evidence that sleep stages are associated with distinct, measurable, reproducible changes in physiology, which is why these signals are reliably used to classify sleep stages.”

Oura said that while its ring is not “a substitute for a clinical sleep study,” its methodology “has been validated and compared favorably in multiple studies” against laboratory sleep studies.

Launched in 2015, Oura has become the most successful smart ring maker, a segment that big tech companies have been unable to capitalize on despite their vast marketing budgets and R&D resources. Over the years, however, the market has gradually shifted toward health-focused wearables.

Earlier this year, Oura filed a draft of its IPO prospectus with the U.S. Securities and Exchange Commission. Last year, Oura announced that it had sold more than 5.5 million Oura Rings since the product’s launch, up from the 2.5 million rings the company said it had sold as of June 2024.