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science nutrition blog

science nutrition <strong>blog</strong>

IGF-1 is a hormone produced in the liver in response to growth hormone that promotes growth during childhood and protein synthesis in adults. A synthetic version of IGF-1 is sold as mecasermin (brand name Increlex) and approved for the treatment of growth failure. Some elite athletes take IGF-1 alone or in combination with IGFBP-3 to build muscle, decrease body fat and improve athletic performance. Researchers from the University of Southampton in the United Kingdom found that the combination of IGF-1 and IGFBP-3 had no effect on body composition in recreational athletes, but increased maximal oxygen consumption by seven percent. The athletes took 60 milligrams per day of the supplement for 28 days. (Journal of Clinical Endocrinology and Metabolism, 100: 3126-3131)