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Peptide Glossary: 50+ Terms Every Beginner Should Know

Getting Started||WPD Research8 min read

This article is for educational and research purposes only. Bookmark this page as a reference — peptide terminology can be confusing at first, but familiarity comes quickly.

A-D

  • Amino acid: The building blocks of peptides and proteins. There are 20 standard amino acids used in human biology.
  • Angiogenesis: The formation of new blood vessels. Some peptides like BPC-157 are studied for their effects on this process.
  • Bacteriostatic water (bac water): Sterile water containing 0.9% benzyl alcohol as a preservative. Used to reconstitute lyophilized peptides for multi-use.
  • Bioavailability: The proportion of a substance that enters circulation and is able to have an active effect. Varies by administration route.
  • BPC: Body Protection Compound. A protein found in gastric juice. BPC-157 is a synthetic fragment of this protein.
  • COA (Certificate of Analysis): A document from a testing lab detailing the identity, purity, and composition of a compound.
  • CJC-1295: A synthetic analog of growth hormone-releasing hormone (GHRH) with a longer half-life than natural GHRH.
  • DAC (Drug Affinity Complex): A modification added to CJC-1295 that extends its half-life by binding to albumin. "CJC-1295 with DAC" vs "without DAC" (also called mod GRF 1-29) have different pharmacokinetic profiles.
  • Desensitization: Reduced response to a compound over time due to receptor downregulation. Some protocols cycle peptides to avoid this.

E-H

  • Endotoxin: Bacterial toxins that can contaminate poorly manufactured peptides. Measured by the LAL (Limulus Amebocyte Lysate) test.
  • GH (Growth Hormone): A 191-amino acid protein hormone produced by the pituitary gland. Many peptides aim to stimulate its natural release.
  • GHRH: Growth Hormone-Releasing Hormone. A natural peptide that stimulates GH release from the pituitary.
  • GHRP: Growth Hormone-Releasing Peptide. A class of synthetic peptides that stimulate GH release through the ghrelin receptor.
  • GLP-1: Glucagon-Like Peptide-1. An incretin hormone involved in glucose metabolism and appetite regulation.
  • Half-life: The time it takes for the concentration of a compound in the blood to decrease by half. Determines dosing frequency.
  • HPLC: High-Performance Liquid Chromatography. The standard analytical method for measuring peptide purity.

I-L

  • IGF-1: Insulin-like Growth Factor 1. A hormone produced by the liver in response to growth hormone. Used as a blood marker for GH activity.
  • IM (Intramuscular): Injection directly into muscle tissue.
  • IU (International Unit): A measurement unit used for some hormones and peptides, particularly HGH.
  • Lyophilized: Freeze-dried. Peptides are typically shipped as lyophilized powder for stability.
  • Loading dose: A higher initial dose used at the start of some protocols to reach therapeutic levels faster.

M-R

  • mcg (microgram): One millionth of a gram. Most peptide doses are measured in micrograms.
  • Mod GRF 1-29: Modified GRF (Growth Hormone-Releasing Factor), also known as CJC-1295 without DAC. A GHRH analog with a short half-life.
  • Peptide bond: The chemical bond linking amino acids together in a chain.
  • Reconstitution: The process of dissolving lyophilized peptide powder in a liquid (typically bacteriostatic water) for injection.

S-Z

  • Secretagogue: A substance that promotes the secretion of another substance. GH secretagogues stimulate growth hormone release.
  • SubQ (Subcutaneous): Injection into the fatty tissue just beneath the skin.
  • Synergy: When two or more peptides used together produce a greater effect than the sum of their individual effects.
  • Titration: Gradually adjusting the dose of a compound, usually starting low and increasing.
  • Upregulation/Downregulation: Increase or decrease in the number or sensitivity of cellular receptors in response to a compound.

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