Peptide glossary

23 definitions about research peptides: from HPLC and COA to reconstitution, storage and laboratory units. All definitions are given for scientific purposes, within the framework of research use (RUO).

Conceptos Básicos

  • Péptido — Short chain of amino acids joined by peptide bonds. They generally contain between 2 and 50 amino acids. They are important signaling molecules in the human body.
  • Aminoácido — Organic molecules that are the building blocks of proteins and peptides. There are 20 standard amino acids in the genetic code.
  • Enlace peptídico — Covalent CO–NH bond between the carboxyl group of one amino acid and the amino group of the next, with the release of a water molecule. The chain of these bonds forms the backbone of the peptide, and the order of the residues it links determines its biological function.

Peptides Específicos

  • GLP-1 (Glucagon-Like Peptide-1) — Hormona incretina producida en el intestino que estimula la secreción de insulina y reduce el apetito. Tirzepatida y Retatrutide son agonistas que incluyen activación del receptor GLP-1.
  • GIP (Glucose-dependent Insulinotropic Polypeptide) — Hormona incretina que trabaja sinérgicamente con GLP-1. Retatrutide activa receptores GIP, GLP-1 y Glucagón simultáneamente.
  • BPC-157 — Body Protection Compound-157. Péptido de 15 aminoácidos derivado de una proteína protectora gástrica. Estudiado por sus propiedades regenerativas en tejidos.
  • TB-500 (Thymosin Beta-4) — Péptido de 43 aminoácidos naturalmente presente en el cuerpo. Investigado por su papel en la regeneración celular y la cicatrización de tejidos.
  • Retatrutide — Triple agonist of GIP, GLP-1 and Glucagon receptors. It represents the latest generation of metabolic peptides with superior results in Phase 3 studies.
  • Hormona de Crecimiento (GH) — Hormone produced naturally by the pituitary, mainly during deep sleep. Some peptides (GH secretagogues) stimulate its endogenous release in pulses, rather than administering it exogenously.

Coenzimas y Cofactores

  • NAD+ — Nicotinamide Adenine Dinucleotide. Coenzyme present in all living cells, crucial for energy metabolism and DNA repair.

Pharmacokinetics

  • Farmacodinamia — The study of what a compound does to the organism: which receptor it binds to, with what affinity, and what biological response it triggers. It is the counterpart of pharmacokinetics, which studies what the organism does to the compound (absorption, distribution, metabolism, and excretion).
  • Vida Media — The time it takes for the concentration of a compound in a biological system to be reduced by half. A key pharmacokinetic parameter in research.
  • Receptor — Cellular protein to which a peptide binds to trigger a specific biological response, analogous to a key and its lock.
  • Biodisponibilidad — Proportion of an administered compound that effectively reaches circulation and exerts its effect. The subcutaneous route has greater bioavailability than the oral route for the vast majority of peptides.
  • In vitro / In vivo — In vitro describe estudios realizados fuera de un organismo vivo (cultivo celular, tubo de ensayo). In vivo describe estudios realizados dentro de un organismo vivo (modelo animal o humano).
  • Preclínico — Research stage prior to human trials, which includes in vitro studies and studies in animal models.

Preparación

  • Reconstitution — The process of dissolving a lyophilized peptide in an appropriate solvent (generally bacteriostatic water) for use.
  • Bacteriostatic Water — Sterile water with 0.9% benzyl alcohol as a preservative. It is the preferred solvent for reconstituting peptides since it allows prolonged storage.
  • Subcutáneo (SC) — Route of administration of the injection beneath the skin, into the fat layer, without reaching muscle or vein. It is the most common route for research peptides.
  • Intramuscular (IM) — Route of injection directly into the muscle, deeper than the subcutaneous route. Only a small number of peptides require it.
  • Insulin syringe — Thin, low-volume syringe (31G gauge, 0.5 or 1 mL) originally designed for insulin, also used to dose reconstituted peptides.
  • Vial — Sealed glass vial containing the lyophilized peptide before reconstitution.

Protocolo y Dosificación

  • Dose — Cantidad de compuesto aplicada por vez, expresada en mg o mcg (no en unidades de jeringa, que dependen de la concentración de cada reconstitución).
  • Titulación — Estrategia de iniciar con una dosis baja e incrementarla gradualmente en el tiempo, permitiendo que el organismo se adapte antes de alcanzar la dosis objetivo.
  • Protocolo — Complete plan for using a compound: which peptide, at what dose, how often, and for how many weeks.
  • Ciclo — Continuous period during which a compound is used before a rest phase (see Off-cycle). The typical duration varies by compound and research objective.
  • Off-cycle — Rest period between cycles, without administration of the compound, which allows assessing the persistence of the effects and restoring the organism's baseline response.
  • Sinergia — Efecto combinado de dos compuestos que resulta mayor que la suma de sus efectos individuales por separado.

Storage

  • Liofilización — Freeze-drying dehydration process that preserves the stability of peptides. Lyophilized peptides have a longer shelf life and are easier to store.
  • Almacenamiento en Frío — Recommended storage conditions for reconstituted peptides (2-8°C). Lyophilized peptides are stable at room temperature.
  • Degradación — Process by which a peptide loses its structure and activity. It can be caused by heat, light, moisture, or oxidation.

Quality Control

  • HPLC — High-Performance Liquid Chromatography. Analytical technique used to verify the purity of peptides. A purity ≥99% indicates a high-quality product.
  • COA (Certificate of Analysis) — Certificate of Analysis. Document that verifies the identity, purity, and quality of a peptide through independent laboratory testing.
  • Espectrometría de Masas — Analytical technique that measures the molecular mass of a peptide to confirm its identity. It complements HPLC analysis.
  • Purity — How clean the compound is: the percentage corresponding to the peptide itself versus residual synthesis impurities. 99% is the reference standard for research material.
  • Lot / Batch — A specific production run of a compound, identified with a unique code. Each batch has its own Certificate of Analysis (COA).

Calidad

  • Grado Premium — Classification indicating a high-purity peptide with verifiable certificates of analysis, suitable for professional use.

Unidades

  • mcg (Microgramo) — Unit of mass equivalent to one millionth of a gram. Peptides are commonly dosed in micrograms.
  • mg (Miligramo) — Unit of mass equivalent to one thousandth of a gram. Used to express the total amount of peptide in a vial.
  • IU (International Units) — Unit of measurement based on the biological activity of a substance, not its mass. Common in peptides such as HGH.