Glatiramer acetate (GA) is a random assortment of L-glutamine, lysine, alanine, and tyrosine. Originally developed in an attempt to produce a synthetic polypeptide to induce experimental autoimmune encephalomyelitis (EAE), GA, instead, prevented or suppressed EAE. Results in animal models led to human trials, in which GA decreased the relapse rate of multiple sclerosis and the amount of new activity on MRI. GA is believed to act, at least in part, by causing a shift from a predominantly proinflammatory Th1 lymphocyte bias to an anti-inflammatory Th2-cell bias. Evidence suggests that GA may exert neuroprotective effects but further study is necessary to establish this as fact.