The U.S. Food and Drug Administration (FDA) has published a July 31, 2015, warning letter targeting the use of whole stevia leaf in food and beverages. Issued to Ten Ren Tea Co. of San Francisco, Ltd., the letter claims that tea products containing “Stevia leaf, tea bag cut” are adulterated under the Federal Food, Drug, and Cosmetic Act “because they bear or contain an unsafe food additive.”

“Any substance added to a conventional food, such as your Ten Ren Chrysanthemum Tea and Hibiscus Spice Tea, must be used in accordance with a food additive regulation, unless the substance is the subject of a prior sanction or is generally recognized as safe (GRAS) among qualified experts for its use in foods [21 CFR 170.30(g)],” notes the agency, which has only permitted highly-refined stevia preparations in specific applications. “[W]e are not aware of any basis to conclude that Stevia leaf is GRAS for use in conventional foods.”

In particular, FDA notes that “literature reports have raised safety concerns about the use of such forms of Stevia, including concerns about control of blood sugar, and effects on the reproductive, cardiovascular and renal systems.” It also deems the tea products misbranded because “the product labels contain information in a foreign language but do not appear to represent all the required label information in both English and the foreign language.”