Peptides are
amino acids broken down into their smaller more digestible form using the hydrolyzation process. Amino acids from peptides are more readily absorbed than free-form amino acids (Glutamine), thus producing a greater insulin reaction. Glutamine Peptides are incredibly nasty tasting. Some reasons to use glutamine peptides:
1. Improved nitrogen -balance
2. Better gut performance
3. Increased immuno-responsiveness
4. Enhancement of glycogen replenishment
5. Prevention of fatigue/overtraining syndrome
If you can choke them down then they are great to use.