This warning about the popular product began circulating on the internet in March 2000. Glucuronolactone is a naturally-occurring metabolite, a carbohydrate produced by the human metabolic system. It most certainly is not "an artificially manufactured stimulant developed in the early 60's by the American Government," as is claimed in the e-mailed exhortation to foreswear the drink. Yet a can of Red Bull contains 600 mg of the substance per can, which has been suggested is 250 times a person's normal daily intake. No proof has yet emerged that this would pose a danger of any sort, but it is a large ...