The majority of glutamine research focused on it's effects on the critically ill and burn patients. So, IV administration is most certainly correct. The problem with oral glutamine administration is that glutamine is a major metabolic fuel for the small intestine. Also, high doses of glutamine have been shown to be absorbed by the kidneys. The result being that little glutamine ingested actually reaches the muscles. So, I would say taking small doses throughout the day would be most efficient as to avoid absorption by the kidneys. Also, for those on a ketogenic diet, glutamine inhibits ketogenesis in the liver. The end result being that ketosis may be difficult to achieve while consuming sufficient quantities of glutamine.