WATCH: Lawsuit accuses Starbucks of mislabeling 8 'sugar-free' protein drinks

The lawsuit was filed by Hagens Berman on behalf of three individuals in California, New York and Washington who all bought Starbucks’ sugar-free protein drinks.

Starbucks introduced protein drinks in September 2025 to meet consumer demand for functional beverages and catch up to rivals like Dutch Bros, which launched protein-enhanced coffee drinks in 2024.