Ghrelin, GHRL gene, obestatin prepropeptide or lenomorelin from ghrelinergic cells in the gastrointestinal tract. GHRL is a neuropeptide in the central nervous system regulating appetite. Ghrelin is regulating the distribution and rate of use of body energy.Hormone releasing factors and releasing hormones are signaling molecules produced by glands in multicellular organisms. The glands that secrete Luteinizing hormones LHRG and LH, FSH comprise the endocrine signaling system. The term growth hormone releasing hormone GHRH is sometimes extended to include chemicals produced by cells that affect the same cell (autocrine or intracrine signaling) or nearby cells (paracrine signaling). Human recombinant LHRG and GHRH are produced in E. coli or in yeast cells.Peptides short amino acid chains or epitopes or blocking antagonists. The shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, tetra peptides, ... till polypeptides that are long, continuous, and unbranched synthetic peptide chains. These biological oligomers and polymers can be Solid-phase peptide synthesis (SPPS), or in continue produced for custom peptide synthesis projects. The High-efficiency solid phase peptide synthesis (HE-SPPS) is give very low production costs.