Glutamine and L-Glutamine are most likely the same thing, it depends on the label. The L means that it is a free form amino acid, rather than peptide bonded which it also could be if it just says Glutamine. Peptide bonded just means that the Glutamine is bonded to another amino. Don't worry about the L since it could be L or D, allthough you will never see D-Glutamine or any other amino acids in D form (its a long story why not). Read the label and ingredients and check if it says Glutamine peptides or L-Glutamine. I am currently taking Legal Gears Pro Complex which contains glutamine peptides and alanine. I'm not sure if it is working. Some companies push that Glutamine can have a cell volumizing affect somewhat like creatine, only not as watery and bloated, so not as noticable. I take it after workout and before bedtime with half a scoop of whey and skim milk. Glutamine has also been said to increase hgh therefore the reason I am taking it at night as well.