HGH peptide therapy is the use of proteins, or peptides – peptides are chains of amino acids that can alter body chemistry by telling other cells what to do. HGH peptides are NOT hormones, but they do stimulate the pituitary gland to produce more human growth hormone (HGH). In most cases, patients notice a significant change by the end of the first month. However, 3-6 months of therapy are needed to experience the full effects.