Kombucha Tea Side Effects and Warnings

Safety Issues

In a set of animal studies, researchers prepared a batch of Kombucha and found that it was essentially nontoxic when taken at appropriate doses. ¹ However, because Kombucha is a complex and variable mixture of microorganisms, it isn't clear that any other batch of the tea would be equally safe. In fact, there are case reports, which suggest that Kombucha preparations can cause such problems as nausea, jaundice, shortness of breath, throat tightness, headache, dizziness, liver inflammation, and even unconsciousness. ² It isn't clear whether the cause of these symptoms is an unusual reaction to a generally nontoxic substance, or a response to unusual toxins that developed in a particular batch of Kombucha.

In addition, there is one case report of severe lead poisoning caused by regular use of Kombucha brewed in a ceramic pot. ³ When brewed or stored in some ceramics, the risk of lead poisoning results because Kombucha tea is acidic. Many ceramic glazes contain a low level of lead that would not make the pottery dangerous for ordinary use; but if an acidic solution like Kombucha is steeped in them for a long time, a dangerous amount of lead may leech into the solution.

There is also one report of Kombucha becoming infected with anthrax and passing along the infection to an individual who rubbed it on his skin to alleviate pain. ⁴ Apparently, anthrax from nearby cows got into the Kombucha mixture and grew.