The FDA has issued a warning letter to Texas-based KetoKerri for selling unapproved new drugs for the treatment of COVID-19.

The agency cited a series of false and misleading statements by the company relating to its supplements, including the suggestion that customers drink “a mixture of chlorine dioxide and water for the prevention and treatment of COVID-19, among other diseases.”

Ingesting chlorine dioxide is not an effective treatment and can cause serious adverse events, the agency said.