Human Growth Hormone is a genetically engineered medicine which is used to treat patients who have growth defects. It is a peptide hormone which stimulates growth, cell reproduction, and cell regeneration in human and animals. A peptide is a short chain of amino acid (molecule) that is held together by peptide bonds. Human Growth Hormone is also a stress hormone which increases the levels of glucose and free fatty acids in humans and animals. It is only available as a prescription drug in the USA.