No, not to my knowledge. My 11 year old has been inhaling and ingesting multiple grams of GSH for almost a full decade now. He does not culture any bacteria, and weighs at the 95th percentile for weight. We have had similar results for our 8 year old and 5 year old. I have searched just about every piece of GSH literature out there, and you can find a summary off the UVICF website for the Investigator's Brochure for GSH. Vitamin C would actually have to be considered more toxic than GSH. I'd say this is a case of your doctor "being down on what he is not up on."