I have literally dozens of research data on Glutamine & Peptide bonded Glutamine given orally to be very effective.
If you want to cover all bases you can use:
2 servings a day of Ener-G (about 11g of glutamine peptides)
2 ISO-AGB a day (about 4g of Acetyl-L-Glutamine)
30grams of regular Glutamine.
There is no evidance that excess Glutamine consumption has any negative impact on one's health, so I prefer taking more than takin less.