The story

The long-R3 family began in Adelaide, Australia, in the early 1990s. Geoffrey Francis, John Ballard and the CSIRO and GroPep team showed that swapping the amino acid at position 3 and adding a front extension let IGF-1 escape its binding proteins and act many times more strongly. Frank Tomas showed these variants kept muscle on rats under steroid stress far better than plain IGF-1. Later variants in the family were sold under new letters, and LR4 is one of these names. Russian endocrinologists describe IGF-1 as the hormone that carries growth hormone's effects into metabolism, cell renewal and ageing.