Glatiramer acetate, formerly called copolymer-1, is one of a series of polypeptide preparations developed to stimulate myelin basic protein, a natural component of the myelin sheath. Myelin basic protein suppresses experimental allergic encephalomyelitis (the animal model of multiple sclerosis); a better suppression effect was demonstrated by use of a synthetic basic copolymer (Teitelbaum et al 1974). This provided the rationale for the use of copolymer in multiple sclerosis. Glatiramer acetate was developed for commercial use, and results of the first clinical trial were published in 1987. The United States Food and Drug Administration approved it in 1996 for use in multiple sclerosis patients.