Animal-free Recombinant Human Human Growth Hormone (HGH) is expressed in human 293 cells with an apparent molecular mass of 22 kDa. It is also known as somatotropin and is a pleiotropic cytokine of the hematopoietic growth factor superfamily. The purity is greater than 95%. It is known primarily for its role in stimulating the development and differentiation of muscle, bone, and cartilage. This cytokine is produced in a serum- free, chemically defined media.