Evans and Long in 1921 demonstrated in animals that a crude extract of the anterior pituitary contained a factor promoting growth. The active principle of the extract of hypophyses was obtained in a purified form by Li and associates. They isolated and described the properties of the growth hormone in 1944 and in 1951 summarized its physiological effect in animals. Wilhelmi, Fishman, and Russell, in 1948, and Raben and Westermyer, in 1951, developed methods for crystallizing growth hormone.
Beck, McGarry, Dyrenfurth, and Venning1 first demonstrated the activity of purified monkey and human pituitary growth extracts in man. Ikkos, Luft, and Gemzell2 studied the effect of human growth hormone (HGH) prepared according to the method of Li and Papkoff, in metabolic studies in four adults, one of whom had been previously hypophysectomized. Ten mg. of HGH, administered daily, had a prompt effect in all of these patients. The effect