Starbucks faces lawsuit over sugar in eight ‘sugar-free’ protein drinks

A Starbucks drink sold as “sugar-free” can contain as much as 21 grams of sugar in a large serving, according to consumers suing the coffee chain. Their complaint centres on lactose, the sugar naturally present in milk, and whether customers should have to look beyond a drink’s name to understand what they are buying. Khaleej Times reported that the dispute covers eight protein beverages.

The proposed class action, a lawsuit seeking to represent a wider group of consumers, was filed on Friday in federal court in Seattle. It seeks unspecified damages over alleged false advertising and breaches of several state consumer protection laws. The consumers say a reasonable buyer would not expect a beverage advertised as sugar-free to contain between 13 and 21 grams of sugar in a 20- or 24-ounce “venti” serving, Starbucks’ name for that size.

A dispute over what ‘sugar-free’ means

The complaint says federal law bars Starbucks from describing drinks as sugar-free when they contain more than 0.5 grams of sugar per 12-ounce serving. That threshold is quoted for a smaller serving than the venti sizes cited in the allegations. The consumers also accuse the company of leaving out federally required notices stating that the protein drinks are not low-calorie foods or intended for weight control.

The products named in the case are the Sugar-Free Vanilla Protein Latte, Sugar-Free Caramel Protein Latte, Sugar-Free Vanilla Protein Matcha and Sugar-Free Caramel Protein Matcha, along with iced versions of each. Starbucks introduced the beverages in September 2025 as part of its updated “Back to Starbucks” menu. The case therefore challenges the marketing of a group of drinks launched under that menu initiative, rather than a single product.

The company’s website describes the beverages as rich in protein and having no added sugar, according to the report. It also discloses that they contain sugars and lists between 270 and 340 calories for venti servings. Those disclosures sit at the centre of the disagreement: the consumers are challenging the sugar-free description because of the lactose already present in the drinks, not merely whether sugar was added.

Starbucks points to its disclosures

Starbucks rejects the allegations. In an emailed response, a spokesperson said the company had clearly and consistently supplied information about the protein drinks, sugar-free choices, ways to customise orders and nutritional content. That information appeared across product announcements, menus, promotional materials, its website and its app, the spokesperson said.

Starbucks says the claims are without merit and that it will vigorously defend itself.

The consumers accuse Starbucks of seeking to benefit from the desire of 75% of Americans to cut back on or avoid sugar. Their case comes against a wider backdrop of food-marketing litigation. The report notes dozens of recent lawsuits disputing sugar-free or zero-sugar labels on products containing allulose, a sugar substitute. The Starbucks complaint, by contrast, focuses on lactose.

A lawyer for the consumers did not immediately respond to requests for further comment. The next point to watch is how Starbucks defends its drink names and disclosures against the consumers’ allegations in Seattle federal court, where the complaint seeks damages without specifying an amount.