Costco is facing a proposed class-action lawsuit over one of its Kirkland Signature drink mixes after a customer alleged that a product advertised as “sugar-free” is misleading because it contains allulose.
The lawsuit centers on Kirkland Signature Hydration Electrolyte Drink Mix, a powdered beverage mix sold by Costco. According to the complaint, Illinois resident Mason Maldonado purchased the product and later claimed he would not have bought it—or would have paid less for it—if he had known that allulose was included as an ingredient.
Allulose is listed as the first ingredient in the drink mix, according to the lawsuit. The complaint argues that because allulose is a monosaccharide, it should be considered a type of sugar under applicable labeling standards.

Costco Facing A Proposed Class-Action Lawsuit Over 'Sugar-Free' Drink
That argument, however, comes with an important distinction: The FDA treats allulose differently from traditional sugars for certain nutrition-labeling purposes.
Under current FDA guidance, manufacturers may exclude allulose from the “Total Sugars” and “Added Sugars” amounts listed on Nutrition Facts labels. Allulose must still be included in “Total Carbohydrates,” and the FDA allows manufacturers to use a lower caloric value for allulose when calculating calories on the label.
The FDA explains that allulose has a chemical structure similar to other sugars but is metabolized differently from traditional sugars. Its guidance specifically says the agency intends to exercise enforcement discretion regarding its exclusion from the Total Sugars and Added Sugars declarations.
The lawsuit, however, takes issue with Costco’s broader use of the “sugar-free” description. The complaint alleges that consumers could interpret the claim to mean the product contains no form of sugar, despite allulose appearing prominently in the ingredient list. The complaint also accuses Costco of what it calls “health-washing,” arguing that the company’s marketing could lead shoppers to view the drink mix as healthier than it is. The lawsuit points to research concerning possible digestive effects associated with consuming allulose, including nausea, bloating, diarrhea and abdominal discomfort.
Those allegations are part of the complaint and have not been established by a court. Maldonado is seeking damages on behalf of himself and other consumers who allegedly purchased the product based on the disputed marketing.
He is also seeking attorneys’ fees and a court order requiring Costco to stop or change the labeling and marketing that he claims is misleading. The proposed class action was filed in the U.S. District Court for the Western District of Washington. Costco has been contacted for comment, according to MyNorthwest.
At the center of the dispute is the difference between what consumers may understand by the phrase “sugar-free” and how allulose is treated under FDA nutrition-labeling guidance.
While the lawsuit argues that the presence of allulose makes Costco’s marketing deceptive, FDA guidance allows the ingredient to be excluded from the Total Sugars and Added Sugars lines on a Nutrition Facts label.

