Dunkin' Zero sugar energy drink allulose lawsuit (Wells v. Dunkin' Brands)

A Chicago customer filed a proposed class action on September 30, 2026, claiming that Dunkin' Zero energy drinks are falsely marketed as having "0g of sugar" because they are sweetened with allulose. The case is Wells v. Dunkin' Brands, Inc. and Inspire Brands, Inc., No. 1:26-cv-14463, in the U.S. District Court for the District of Massachusetts.

Dunkin' launched Dunkin' Zero on March 4, 2026, as a "zero-sugar energy drink." The complaint says each medium drink contains about 8 to 10 grams of allulose and each large about 11 to 13 grams, and that allulose is a sugar under federal labeling rules.

The lawsuit seeks to represent everyone in the United States who bought a Dunkin' Zero drink at a Dunkin' restaurant since March 4, 2026, plus an Illinois subclass. No court has ruled on the claims, and no class has been certified.

Dunkin' Brands, Inc. is a Delaware corporation headquartered in Canton, Massachusetts. According to the complaint, it owns and franchises the Dunkin' brand in the United States and develops the drinks and marketing used at roughly 10,000 Dunkin' restaurants. Inspire Brands, Inc., based in Atlanta, acquired Dunkin' in December 2020 and, the complaint says, approves the brand's products and marketing.

The plaintiff is Phyllis C. Wells of Chicago. The complaint says she has bought Dunkin' Zero drinks two to three times a week at a Chicago drive-through since the launch, paid by card and kept her statements. She says she tries to limit sugar and relied on the "zero sugar" claims.

She is represented by Patton Legal, P.C. of Boston, with lawyers from Strauss Borrelli PLLC and Levin Law, P.A. seeking permission to appear.

Dunkin's March 4, 2026 press release announced Dunkin' Zero as "a zero-sugar energy drink" that "delivers 20 calories in a medium and zero grams of sugar." The launch flavors were Blackberry Tangerine, Tropical Mango and Juicy Peach, plus three combinations called Glamberry, Sunzest and Blushpop. According to the complaint, Watermelon Lime, Splashberry, Heatwave and Melon Paradise were added later.

The complaint says Dunkin's menu pages describe each drink as having "0g of sugar," and that the same message appears on menu boards, social media and promotions. It says Dunkin's own Allergen and Ingredient Guide lists allulose as the first ingredient after water in each flavor syrup.

The complaint also cites Dunkin's Nutrition Guide, which it says lists 9 grams of total carbohydrate in a medium Blackberry Tangerine drink and zero grams of total and added sugars. Because allulose is the main carbohydrate ingredient, the plaintiff alleges that most of that carbohydrate is allulose.

Federal rules allow "zero sugar" and similar claims only when a food has less than 0.5 grams of sugars per serving and no sugar ingredient without a disclosure. Those rules define sugars as all free mono- and disaccharides. Allulose is a monosaccharide. In 2020, the FDA said it would not enforce allulose's inclusion in the sugar lines on Nutrition Facts labels. On July 27, 2026, the Seventh Circuit held in Franco v. Chobani that allulose still counts as a sugar under the federal definition, and the FDA said in that case that its guidance did not cover sugar-free claims.

The plaintiff argues that "zero sugar" and "0g of sugar" are absolute promises that reasonable consumers read as meaning no sugar at all. She says buyers paid a price premium and that Dunkin' gained an unfair edge over competitors. She also says the claims are illegal nutrient content claims under federal rules that Illinois and Massachusetts law mirror.

The complaint brings four claims: violation of the Illinois Consumer Fraud and Deceptive Business Practices Act for the Illinois subclass, and breach of express warranty under Massachusetts law, negligent misrepresentation and unjust enrichment for the nationwide class. It says the plaintiff plans to add a Massachusetts consumer protection claim after a required notice period.

Class Action Pulse found no public statement from Dunkin' or Inspire Brands about the lawsuit, and the docket showed no response from either company as of October 19, 2026.

The case was first assigned to Magistrate Judge Jennifer C. Boal, and the clerk issued summonses for both companies on September 30. The docket shows a magistrate judge consent filing on October 6, another notice of case assignment on October 7, two out-of-state lawyer applications on October 17, and an order on a request to appear on October 19.

The court has not decided whether allulose makes the claims false, whether customers were misled or whether a class should be certified.

The complaint proposes two groups:

• Nationwide Class: all persons in the United States who, from March 4, 2026, through the date of class certification, bought one or more Dunkin' Zero drinks from a Dunkin' restaurant for personal, family or household use.
• Illinois Subclass: the same buyers whose purchases were at a Dunkin' restaurant in Illinois.

The groups exclude the defendants and their affiliates, officers, directors, employees and franchisees, the assigned judges and their staff and families, and the lawyers in the case. The complaint covers every drink sold under the Dunkin' Zero name, in all sizes.

There is no claim form and no deadline. Buyers can:

• Check card statements or the Dunkin' app order history for Dunkin' Zero purchases since March 4, 2026.
• Note the flavor, size and restaurant location where possible.
• Watch for any class certification ruling or settlement notice.
• Contact Patton Legal or their own lawyer with questions.

There is no money available. The complaint asks for actual damages, punitive damages under the Illinois law, restitution, an order requiring Dunkin' to stop the "zero sugar" claims and correct the public impression, interest and attorneys' fees. These are requests, not awards.

• March 4, 2026: Dunkin' Zero launches, starting the proposed class period.
• July 27, 2026: Seventh Circuit decides Franco v. Chobani.
• September 30, 2026: complaint filed and summonses issued.

No claim, opt-out or objection deadlines exist. If a class is certified or a settlement is reached, notice would explain members' options.

• Allulose: A low-calorie simple sugar used as a sweetener, about 70% as sweet as table sugar according to the complaint.
• Monosaccharide: A single-unit sugar, such as glucose or fructose.
• Nutrient content claim: A statement about how much of a nutrient a food contains, such as "zero sugar."
• Express warranty: A seller's specific promise about a product that can be enforced if untrue.
• Price premium: The extra amount a buyer allegedly paid because of a claim.

Dunkin' and Inspire Brands are expected to respond, likely with a motion to dismiss. Class Action Pulse also covers a similar allulose case against Costco, which shows how often these claims are now being tested.

A practical note: app and card records are the easiest proof for drive-through purchases, so a quick screenshot of past orders can help if paper receipts are gone.

This article relies on the complaint, the court docket, Dunkin's March 4, 2026 press release, the Seventh Circuit's Franco v. Chobani opinion, the FDA's amicus brief, and ClassAction.org.

The allulose amounts, the price premium and the deception claims are allegations. The text of the October 7 assignment notice and October 19 order was not available. Sales volume and class size are unknown.

Class Action Pulse is not a law firm or settlement administrator and does not guarantee eligibility or payment. This article is general information, not legal advice.