332f662d_Supplements_for_Pain__effectiveness
[supplement & summary] Glutamine & Arginine. Abundant but non-essential amino acids (protein building blocks), mainly stored in muscle. Depleted in the critically ill, glutamine is used medically to aid tissue repair. Athletes and bodybuilders imagine running low on these substances after harsh workouts and hope “topping them up” will help repair/build muscle. See detailed section below for much more. Both of these amino acids have a mess of barely understood properties which might be relevant to exercise performance and recovery,10 such as anti-inflammatory effect,11 stimulation of growth hormone production,12 or dilating blood vessels.13 [safety] both are generally well tolerated, but have long lists of possible side effects and numerous safety concerns for chronic supplementation: “neurological effects were the most frequently observed” problems with glutamine14, and arginine is “associated with death in certain groups of heart patients”15 [more information] no good sources known16 [effectiveness] 
nearly unstudied in the context of athletic performance and recovery, some promising scraps of basic science only; conflicting evidence even for medical use with critically ill patients
Supplements for Pain
effectiveness