An investigation by Consumer Reports found elevated lead levels in some bubble tea products in the US, raising concerns similar to past warnings about cassava-based foods.

Additionally, the pearls themselves can cause digestive problems. As they are dense and starchy, eating large amounts can cause gastroparesis, or in rare cases, a complete blockage. Guar gum may also contribute to constipation when consumed frequently.

Other health concerns around bubble tea found include increased risk of kidney stones and the danger of choking on tapioca pearls, as well as the high levels of sugar, which sometimes exceed those of a can of Coca-Cola.