Glutamine is the most abundant free amino acid in the body. It is produced in the muscle and then gets distributed by blood. 61% of our glutamine is stored in skeletal muscle and it consists of 19% nitrogen, making it the primary transporter of nitrogen into your muscle cells. Glutamine is a kind of nitrogen sponge. It mops up ammonia and shuttles nitrogen between different tissues (such as muscle), where it can be used for cell growth and tissue repair, among many other functions. Alongside that it also provides “fuel” to cells in our body.
Do I need to supplement? Not necessarily. Supplementing with glutamine may have an effect when the body uses more glutamine than the muscles can make (during times of stress, extremely hard workouts…). A lack of glutamine can then cause muscle wasting. Your body is supposed to be making the essential amount naturally though.
Summarized, yes, try taking glutamine if you really go hard in the gym. It may help you preserve muscle.