Peptide Research Glossary

This glossary provides definitions of key terms used in peptide research. All products referenced are sold by 13 Peptides for research and laboratory use only.

A

Amino Acid: An organic molecule containing both an amino group (-NH2) and a carboxyl group (-COOH). Amino acids are the building blocks of peptides and proteins. There are 20 standard amino acids encoded by the genetic code, each with a unique side chain that determines its chemical properties.
AOD-9604: Anti-Obesity Drug 9604, a modified fragment (amino acids 177-191) of human growth hormone. This synthetic peptide is researched for its effects on lipid metabolism. Available from 13 Peptides in 5mg and 10mg lyophilized form.
Alpha-MSH (Alpha-Melanocyte-Stimulating Hormone): A 13-amino acid peptide hormone produced in the pituitary gland. Alpha-MSH is involved in melanogenesis and pigmentation pathways. KPV and Melanotan 2 are synthetic peptides related to alpha-MSH signaling.

B

Bacteriostatic Water: Sterile water containing 0.9% benzyl alcohol as a preservative to inhibit bacterial growth. Commonly used as a solvent for reconstituting lyophilized peptides in research settings.
BPC-157 (Body Protection Compound-157): A synthetic pentadecapeptide (15 amino acids) derived from a protein found in human gastric juice. BPC-157 is one of the most widely studied cytoprotective peptides in research literature. Available from 13 Peptides as a single 10mg vial or in blends including BPC-157/TB-500.

C

CJC-1295 (no DAC): A synthetic analog of Growth Hormone-Releasing Hormone (GHRH) modified for enhanced stability. The “no DAC” designation indicates the version without Drug Affinity Complex, resulting in a shorter half-life. Available in a blend with Ipamorelin.
Certificate of Analysis (COA): A quality document issued by an analytical laboratory that reports testing results for a specific batch of product. For peptides, a COA typically includes HPLC purity data, mass spectrometry identity confirmation, physical appearance, and batch identification. Every 13 Peptides product includes a COA.
Cytoprotective: Describing a substance or mechanism that protects cells from damage or death. In peptide research, BPC-157 and TB-500 are among the most studied cytoprotective peptides.

E

Epithalon (Epitalon): A synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly, based on the natural peptide Epithalamin isolated from the pineal gland. Researched primarily for its effects on telomerase activity. Available from 13 Peptides in 10mg and 50mg form.

G

GHK-Cu (Glycyl-L-Histidyl-L-Lysine Copper): A naturally occurring copper-binding tripeptide first identified in human plasma by Dr. Loren Pickart in 1973. GHK-Cu is researched for its roles in skin biology and tissue remodeling. Available from 13 Peptides in 50mg and 100mg form.
GHRH (Growth Hormone-Releasing Hormone): A 44-amino acid peptide hormone produced in the hypothalamus that stimulates growth hormone release from the anterior pituitary. Sermorelin and Tesamorelin are synthetic GHRH analogs used in research.
Growth Hormone Secretagogue (GHS): A class of compounds that stimulate growth hormone release by binding to the Growth Hormone Secretagogue Receptor (GHS-R). Research peptide examples include Ipamorelin, Sermorelin, and Tesamorelin.
Glutathione: A tripeptide (Glu-Cys-Gly) that serves as the body’s primary intracellular antioxidant. Researched for its roles in detoxification, oxidative stress response, and cellular protection. Available from 13 Peptides as 1500mg lyophilized.

H

HPLC (High-Performance Liquid Chromatography): An analytical technique used to separate, identify, and quantify components in a mixture. In peptide quality control, reversed-phase HPLC is used to measure purity by separating the target peptide from synthesis impurities. Research-grade peptides typically achieve 98%+ HPLC purity.

I

Ipamorelin: A selective growth hormone secretagogue that binds to the GHS-R receptor. Unlike some other GHS peptides, Ipamorelin is studied for its selectivity in stimulating GH release without significantly affecting cortisol or prolactin. Available from 13 Peptides in 5mg and 10mg form.

K

KPV: A tripeptide (Lys-Pro-Val) derived from the C-terminal region of alpha-melanocyte-stimulating hormone. Researched for its signaling in anti-inflammatory pathways. Available from 13 Peptides as 5mg lyophilized.

L

Lyophilization (Freeze-Drying): A dehydration process in which a frozen solution is placed under vacuum, causing the ice to sublimate (transition directly from solid to gas) without passing through a liquid phase. Lyophilization preserves peptide stability for long-term storage. All 13 Peptides products are supplied in lyophilized form.

M

Mass Spectrometry (MS): An analytical technique that measures the mass-to-charge ratio of ions. In peptide analysis, mass spectrometry confirms molecular identity by verifying that the measured molecular weight matches the theoretical weight calculated from the amino acid sequence.
Melanotan 2: A synthetic cyclic analog of alpha-melanocyte-stimulating hormone researched for melanocortin receptor binding activity. Available from 13 Peptides as 10mg lyophilized.
MOTS-c: A mitochondrial-derived peptide encoded by the 12S rRNA gene of the mitochondrial genome. MOTS-c is researched for its roles in metabolic homeostasis, AMPK activation, and exercise physiology. Available from 13 Peptides as 10mg lyophilized.

N

NAD+ (Nicotinamide Adenine Dinucleotide): A coenzyme found in all living cells that exists in oxidized (NAD+) and reduced (NADH) forms. NAD+ is essential for cellular energy metabolism, DNA repair, and sirtuin activation. Available from 13 Peptides as 1000mg lyophilized.

P

Peptide: A short chain of amino acids (typically 2-50 residues) linked by peptide bonds. Peptides are distinguished from proteins by their smaller size. In biological systems, peptides function as hormones, neurotransmitters, and signaling molecules. See What Are Research Peptides? for a comprehensive overview.
Peptide Bond: A covalent chemical bond formed between the carboxyl group of one amino acid and the amino group of another, with the release of a water molecule. Peptide bonds form the backbone of all peptides and proteins.
PT-141 (Bremelanotide): A synthetic peptide and melanocortin receptor agonist. PT-141 is a cyclic heptapeptide analog of alpha-MSH metabolite. Available from 13 Peptides as 10mg lyophilized.

R

Reconstitution: The process of dissolving a lyophilized (freeze-dried) peptide powder back into solution using an appropriate solvent, typically bacteriostatic water. See our guide: How to Reconstitute Lyophilized Powders.

S

Selank: A synthetic peptide analog of the immunomodulatory peptide tuftsin, developed at the Institute of Molecular Genetics in Russia. Researched for cognitive and anxiolytic properties. Available from 13 Peptides in a blend with Semax.
Semax: A synthetic heptapeptide analog of the ACTH(4-7) fragment, also developed in Russia. Researched for nootropic and neuroprotective properties. Available from 13 Peptides in a blend with Selank.
Sermorelin: The shortest functional fragment of GHRH, consisting of the first 29 amino acids of the 44-amino acid GHRH molecule. Sermorelin is a growth hormone secretagogue used in pituitary function research. Available from 13 Peptides as 5mg lyophilized.
SPPS (Solid-Phase Peptide Synthesis): The primary method for manufacturing synthetic peptides, developed by Robert Bruce Merrifield (Nobel Prize, 1984). SPPS builds peptide chains one amino acid at a time on an insoluble resin support, enabling rapid and automated synthesis of peptides up to approximately 50 amino acids.

T

TB-500 (Thymosin Beta-4 Fragment): A synthetic peptide corresponding to the active region of Thymosin Beta-4, a 43-amino acid protein involved in cell migration and tissue repair. TB-500 is one of the most widely researched cytoprotective peptides. Available from 13 Peptides as 10mg lyophilized.
Tesamorelin: A synthetic GHRH analog with a trans-3-hexenoic acid group that enhances its metabolic stability. Researched as a growth hormone secretagogue. Available from 13 Peptides as 10mg lyophilized.
Thymosin Alpha-1: A 28-amino acid peptide originally isolated from thymic tissue (Thymosin Fraction 5). Researched for its roles in immune cell maturation, T-cell differentiation, and immune response modulation. Available from 13 Peptides as 10mg lyophilized.

All products referenced in this glossary are sold by 13 Peptides for research and laboratory use only. Not for human consumption. For more information, see our FAQ and What Are Research Peptides? guide.