Up until the mid 1980's human growth hormone only comes from extracted pituitary glands of cadavers obtained mostly from Africa. In the mid 1980's cadaver human growth hormone was pulled off the market after discovering contaminated cadaver human growth hormone was found to cause a rare disease called Creutzfeld-Jacob disease(CJD) in the patients, mostly children, who were administering it.
In 1985 the Eli Lily pharmaceutical company managed to synthetically copy the DNA of human growth hormone exactly in their lab. This bio-synthetic form of human growth hormone or recombinant human growth hormone (rHGH) is manufactured by protein expression in a culture such as E. coli, but perfect reproduction of the 191 amino acids does not always occur. Unfortunately, changes in peptide sequence or post-translational modifications to particular amino acid residues have been linked to biological inactivity and disease.
Nowadays, human growth hormone is synthezised for use as a clinical drug mainly to treat patients with growth hormone deficiency and also as a muscle-building drug for athletes and as a health supplement for the general public. It is on the banned list of the World Anti-Doping Agency, but is still actively marketed, although accurate knowledge of human growth hormone and its effects is questionable in some cases
There are various ways to increase human growth hormone level artificially, and they are: