Other amino's shouldn't interfere with it's entry into the cell,as it is the primary amino present in cell occupancy.It could be that you are already getting ample glutamine concentrations through your diet,which may be why you don't notice the volumization effects to any great degree...BTW,glutamine doesn't possess DRAMATIC instant,feelable effects like creatine,it is certainly more subtle in this regard.BUT-it's ability to improve intracellular machinery and processes which are vital to us as bodybuilders(primarily repair)are very important.