Sugar-free drink but still has sugar? Why is Starbucks facing a lawsuit?

Starbucks is facing a consumer lawsuit in the US over claims that some of its protein drinks marketed as “sugar-free” contain significant amounts of sugar.

A federal lawsuit filed in Seattle on Friday alleges that eight Starbucks protein beverages sold in the US contain sugar despite being labelled and marketed as sugar-free.

The lawsuit was filed by Hagens Berman, a law firm specialising in class-action cases, on behalf of three consumers from California, New York and Washington. The plaintiffs claim Starbucks’ labelling and marketing of the drinks is “false, deceptive and unlawful” and violates federal regulations.

The case points to Starbucks’ Sugar-Free Caramel Protein Matcha as one example. The company’s US website listed 16 grams of sugar in a 16-ounce serving and 21 grams in a 20-ounce serving. A Reese’s peanut butter cup, by comparison, contains 11 grams of sugar.

Starbucks said the sugar in its protein drinks comes from the protein-enriched milk used to make them, rather than added sugar. The company said it uses sugar-free syrups for flavouring and does not add sugar to the beverages.

Although Starbucks’ website markets the drinks as “sugar-free”, it also displays their nutritional information and states that they are made without added sugar.

“We believe these claims have no merit,” a Starbucks spokesperson said. The company added that it had consistently provided information about its protein beverages, sugar-free options, customisation choices and nutritional content across its website, app, menus and marketing materials.

The plaintiffs are seeking damages on behalf of US consumers who purchased the drinks. They are also asking the court to order Starbucks to stop describing products as “sugar-free” if they contain sugar.

Starbucks introduced its protein drinks in September 2025 as it sought to respond to growing demand for functional beverages and compete with rivals such as Dutch Bros, which launched protein-enhanced coffee drinks in 2024.

Dutch Bros also sells a lower-sugar caramel protein latte, but markets it as a “Zero Sugar Added Protein Latte”. Its 16-ounce iced version contains 7 grams of sugar and 11 grams of protein.

A 16-ounce iced Starbucks Sugar-Free Caramel Protein Latte, meanwhile, contains 9 grams of sugar and 29 grams of protein, according to the nutritional information cited in the lawsuit.