CJC-1293 or Modified GRF 1-29 (sometimes modGRF 1-29), is a tetrasubstituted 29-amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

 peptide hormone

Peptide hormone

Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals.Like other proteins, peptide hormones are synthesized in cells from amino acids according to an mRNA template, which is itself synthesized from a DNA template inside the...

, primarily functioning as a growth hormone releasing hormone

Growth hormone releasing hormone

Growth-hormone-releasing hormone , also known as growth-hormone-releasing factor , somatoliberin or somatocrinin, is a releasing hormone for growth hormone...

 (GHRH) analog

Functional analog

Functional analogs , are compounds that have similar physical, chemical, biochemical, or pharmacological properties. An example of a functional analog is morphine and heroin. Functional analogs are not necessarily also structural analogs with a similar chemical structure...

 with D-Ala, Gln

GLN

GLN or GLn may refer to:* Glutamine, the most abundant naturally occurring amino acid in the human body* Global Location Number, a thirteen digit number used to identify parties and physical locations...

, Ala, and Leu

Leucine

Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...

 substitutions at positions 2, 8, 15, and 27 respectively. These substitutions create a much more stable peptide with the substitution at position 2 to prevent DPP-IV cleavage, position 8 to reduce asparagine

Asparagine

Asparagine is one of the 20 most common natural amino acids on Earth. It has carboxamide as the side-chain's functional group. It is not an essential amino acid...

 rearrangement or amide hydrolysis to aspartic acid

Aspartic acid

Aspartic acid is an α-amino acid with the chemical formula HOOCCHCH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins...

, position 15 to enhance bioactivity, and position 27 to prevent methionine

Methionine

Methionine is an α-amino acid with the chemical formula HO2CCHCH2CH2SCH3. This essential amino acid is classified as nonpolar. This amino-acid is coded by the codon AUG, also known as the initiation codon, since it indicates mRNA's coding region where translation into protein...

 oxidation.