Oura, the smart ring company that recently entered the South Korean market, is facing a class-action lawsuit in the United States over allegations of false advertising regarding its product performance.

According to the U.S. District Court for the Northern District of California on the 21st (local time), Clarkson Law Firm filed a class-action lawsuit against Oura, representing California resident Madison Carver as the lead plaintiff.

The plaintiffs claimed they suffered damages because, after purchasing and using an Oura product in May of last year, it failed to accurately measure sleep duration, awakenings, and sleep quality.

They went on to criticize Oura for lacking the capability to directly detect physiological signals essential for measuring sleep stages, such as brainwaves, eye movements, and jaw muscle activity. They pointed out that Oura acknowledged this in its own technical documents—noting that discrepancies could arise from polysomnography (PSG) due to the lack of brainwave or eye movement measurements—while simultaneously running contradictory public advertisements.

Oura has advertised through marketing materials and promotions that its products achieve a 79% accuracy rate in measuring sleep stages, with the latest model reaching up to 95% accuracy.

The company also claimed that an internal scientific team consisting of more than 25 PhD-level researchers had validated the products.

Founded in 2013 and headquartered in San Francisco, California, Oura was valued at 11 billion USD (approx. 15.2 trillion KRW) in an investment round in October of last year, sold 3 million smart rings last year, and surpassed 1 billion USD in annual revenue.

The company is currently pursuing an initial public offering (IPO), having confidentially submitted its IPO application to the U.S. Securities and Exchange Commission (SEC) last May.

(Photo: AP, Yonhap News)