Reference
Peptide research glossary
Plain-language definitions of the terms used across our guides and product pages — reconstitution, the growth-hormone axis, incretin receptors, analytical testing and more. For laboratory research context only.
A
- Amino acid
- The building block of peptides and proteins. Amino acids link through peptide bonds to form chains; the specific sequence defines a peptide’s identity.
- Peptide
- Analogue
- A compound whose structure is deliberately modified from a natural molecule to change properties such as stability or receptor selectivity. Many research peptides (for example GHRH analogues) are analogues of endogenous signalling molecules.
B
- Bacteriostatic water
- Sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and allows a reconstituted vial to be drawn from multiple times. It is the solvent most commonly used to reconstitute lyophilised research peptides in the laboratory.
- Bacteriostatic waterReconstitution guide
- BDNF (Brain-Derived Neurotrophic Factor)
- A protein that supports neuron survival and plasticity. Changes in BDNF expression are a frequently studied readout in cognitive and neuroprotection research involving peptides such as Semax.
- SemaxSemax vs Selank
C
- CAS number
- A unique numeric identifier assigned by the Chemical Abstracts Service to a specific chemical substance. It is the most reliable way to confirm compound identity across suppliers and literature.
- COA (Certificate of Analysis)
- A document reporting a batch’s analytical results — typically identity and purity by HPLC and mass spectrometry, plus a batch number. A COA certifies what was tested for that lot; it does not by itself guarantee any other batch.
- Sourcing & transparency
- Concentration
- The amount of peptide dissolved per unit volume of solvent, usually expressed as mg/ml or mcg/ml. It is calculated as vial mass divided by reconstitution volume.
- Reconstitution guidePeptide calculator
- Copper peptide
- A peptide that binds a copper ion, the best-known example being GHK-Cu (glycyl-L-histidyl-L-lysine plus copper). Copper peptides are studied in skin, collagen, and wound-repair research.
- GHK-CuCopper peptide research
G
- GHRH (Growth Hormone-Releasing Hormone)
- A hypothalamic peptide that signals the pituitary to synthesise and release growth hormone. CJC-1295 and Tesamorelin are GHRH analogues studied in the growth-hormone axis.
- CJC-1295 No DACTesamorelinGH secretagogues compared
- GHRP (Growth Hormone-Releasing Peptide)
- A class of synthetic peptides — Ipamorelin is a common example — that trigger growth-hormone release through the ghrelin receptor (GHSR), a pathway separate from GHRH.
- IpamorelinGH secretagogues compared
- GIP (Glucose-dependent Insulinotropic Polypeptide)
- An incretin hormone involved in insulin signalling. Some multi-receptor research peptides act on the GIP receptor alongside GLP-1, and retatrutide adds glucagon-receptor activity on top.
- RetatrutideIncretin receptor signalling
- GLP-1 (Glucagon-Like Peptide-1)
- An incretin hormone that stimulates insulin release, suppresses glucagon, and slows gastric emptying. Semaglutide is a single-receptor GLP-1 agonist; retatrutide is a triple GLP-1/GIP/glucagon agonist.
- SemaglutideRetatrutideRetatrutide vs Semaglutide vs Tirzepatide
- Glucagon receptor
- A receptor whose activation influences energy expenditure and hepatic glucose handling. Triple agonists such as retatrutide add glucagon-receptor activity to GLP-1 and GIP activity.
- Retatrutide
- Growth hormone secretagogue
- Any compound that prompts the body to release its own growth hormone, whether through the GHRH pathway or the ghrelin-receptor (GHRP) pathway. The two families are frequently studied together.
- Growth hormone axis signallingGH secretagogues compared
H
- Half-life
- The time for a compound’s plasma concentration to fall by half. Half-life shapes how a peptide behaves in a study — short-acting peptides clear within minutes to hours, while modified analogues can persist for days.
- Analogue
- HPLC (High-Performance Liquid Chromatography)
- An analytical technique that separates the components of a sample to measure a peptide’s purity, usually reported as a percentage on a certificate of analysis.
I
- Incretin
- A gut hormone — GLP-1 and GIP are the two principal ones — that amplifies insulin release after nutrient intake. Incretin-receptor peptides are a heavily studied class in metabolic research.
- Incretin receptor signalling
L
- Lyophilisation (freeze-drying)
- A process that removes water from a peptide under vacuum to create a stable dry powder. Lyophilised peptides store far longer than solutions and are reconstituted before research use.
- Storage in a tropical climate
- Lyophilisate
- The dry powder produced by lyophilisation — the form in which a research peptide typically arrives in its vial, before reconstitution.
- Reconstitution guide
M
- Mass spectrometry
- An analytical method that measures a molecule’s mass to confirm a peptide’s identity. On a certificate of analysis it complements HPLC, which measures purity.
- MC4R (Melanocortin-4 receptor)
- A central-nervous-system receptor involved in appetite and sexual-arousal pathways. PT-141 (bremelanotide) is a melanocortin-receptor agonist studied at MC3R/MC4R.
- PT-141Neuroendocrine signalling
- Mitochondrial-derived peptide
- A small peptide encoded within mitochondrial DNA, such as MOTS-c, studied for its role in cellular energy metabolism and metabolic-stress signalling.
- MOTS-cMitochondrial & cellular research
- Molecular formula
- The count of each element in a molecule (for example C62H98N16O22 for BPC-157). With the sequence and CAS number, it helps confirm a peptide’s identity.
N
- NAD+ (Nicotinamide Adenine Dinucleotide)
- A coenzyme central to cellular energy metabolism and DNA-repair pathways. NAD+ and its precursors are studied widely in cellular-ageing and mitochondrial research.
- NAD+Mitochondrial research compounds
- Nootropic
- A compound studied for effects on cognition, learning, or memory. Among research peptides, Semax and Selank are the most commonly referenced nootropic candidates.
- SemaxSelankNeuropeptide signalling
P
- Peptide
- A short chain of amino acids joined by peptide bonds, typically 2–50 residues long. Most research peptides fall in the 5–30 residue range; longer chains are classed as proteins.
- Amino acid
- Proteolysis
- The enzymatic breakdown of peptides by proteases. Rapid proteolysis is why many native peptides have short half-lives, and why analogues are engineered for stability.
- Half-life
- Purity
- The proportion of a sample that is the intended peptide, as opposed to related impurities, usually measured by HPLC and stated as a percentage on a certificate of analysis for that batch.
R
- Reconstitution
- Dissolving a lyophilised peptide powder in a solvent — most often bacteriostatic water — to prepare a solution for research use. The solvent is added slowly against the vial wall and swirled, not shaken.
- Reconstitution guideBacteriostatic water
- Research use only (RUO)
- A supply-and-labelling category meaning a product is intended for laboratory research and is not a medicine, supplement, or food, and not for human or veterinary use. It carries no dosing or treatment guidance.
- Research-use disclaimer
S
- Sequence
- The ordered list of amino acids in a peptide, written from the N-terminus to the C-terminus. The sequence defines the molecule and distinguishes it from related compounds.
- Subcutaneous (SC)
- Delivery into the fat layer beneath the skin — the route used in most animal studies of research peptides. Referenced here to describe how compounds were administered in the published literature, not as guidance for any other use.
T
- Thymosin beta-4
- A naturally occurring protein involved in actin regulation and cell migration. TB-500 is a synthetic fragment corresponding to an active region of thymosin beta-4, not the full protein.
- TB-500BPC-157 vs TB-500
V
- VEGF (Vascular Endothelial Growth Factor)
- A signalling protein that drives the growth of new blood vessels. VEGF modulation is a mechanism frequently reported in preclinical BPC-157 angiogenesis studies.
- AngiogenesisBPC-157
- Vial
- The sealed glass container holding a lyophilised peptide powder before reconstitution, commonly in 1–10 mg sizes. Vials are kept sealed, cool, and out of direct light until used.
- Storage in a tropical climate
For laboratory research use only. Not for human or veterinary use.