One of the few supplements out there that can truly blunt cortisol is phosphatidylserine. But you need the proper amounts, and they are exceedingly higher than the doses that are sold in pill form. Your best bet is to go somewhere like kilosports and get a kg. of it in powder form. There's a lot of science behind it, and the shit does work. Very pricey stuff, but has an anti-catabolic effect about 5 times as effective as high dose glutamine.