Popular health-conscious soda alternative, Poppi, is being sued in a class-action lawsuit alleging the beverages are not as healthy as advertised.

Posed as a gut-friendly and healthier alternative to traditional sodas, Poppi has gained an almost cult-like following for its prebiotic drinks infused with apple cider vinegar and inulin, a prebiotic power, while containing no more than five grams of sugar and 25 calories.

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However, a lawsuit filed last week in a California court accuses the company of false advertising, claiming that the cans only contain two grams of prebiotic fiber per serving.

The lawsuit alleges that the average consumer would have to drink at least four cans of Poppi for 21 consecutive days to see the prebiotic benefit, which would be negated by the total amount of sugar found in the beverages.

Poppi claims on its label that each can contains at least 2 grams of prebiotic fiber. According to data cited from Very Well Health, the average consumer would need to ingest more than 7.5 grams of dietary prebiotic fiber to achieve gut-friendly health benefits.

“Although Poppi’s rise in popularity can be attributed to its enticing flavors and clever marketing, the core of Poppi’s success is primarily owed to a particular ingredient: agave inulin, the Products’ so-called ‘Prebiotic,'” the lawsuit states. “But, despite Poppi’s “prebiotic” marketing claims, which assure consumers, on the can, that they can ‘Be Gut Happy [and] Be Gut Healthy,’ as one nutritionist bluntly explained: the Products ‘are basically sugared water.'”

The lawsuit is seeking $500,000 in damages and also claims that Poppi can lead to adverse health effects, such as liver damage, diarrhea, and bloating.

“An inulin-based diet can lead to inflammation and even liver damage at doses as small as 10 to 30 grams per day over a 3-week period,” the lawsuit says, citing data from the National Institute of Health.

Poppi is defending against the lawsuit.

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“We are proud of the Poppi brand and stand behind our products,” a spokesperson for Poppi told Entrepreneur in a statement via email. “We are on a mission to revolutionize soda for the next generation of soda drinkers, and we have diligently innovated to provide a tasting experience that millions of people have come to enjoy. We believe the lawsuit is baseless, and we will vigorously defend against these allegations.”

Poppi quickly became a viral sensation after founders Allison and Stephen Ellsworth scored a deal on Season 10 of “Shark Tank” with Rohan Oza, who offered the couple $400,000 for a 25% stake.