Research Peptide Glossary
Plain-English definitions of the terms used across our research articles — from analytical methods to receptor biology.
- Bacteriostatic water
- Sterile water containing 0.9% benzyl alcohol as a preservative, used to reconstitute lyophilized peptides for research. The preservative allows a multi-use vial to be stored refrigerated between uses. How to reconstitute peptides →
- Certificate of Analysis (COA)
- A document from an independent third-party lab certifying a specific lot's identity, purity, and the absence of contaminants. The lot number on the COA must match the lot number on the vial. How to read a COA →
- cAMP pathway
- A cell-signaling cascade triggered when a hormone (like GHRH) binds its receptor and activates adenylyl cyclase, raising intracellular cyclic AMP. One of the two principal pathways driving growth-hormone release from the pituitary. CJC-1295 + Ipamorelin synergy →
- DPP-4 resistance
- A structural modification (often a single amino-acid substitution) that prevents the enzyme dipeptidyl peptidase-4 from rapidly degrading a peptide, extending its half-life in research models. What is GLP-2? →
- Elimination half-life
- The time it takes for a compound's concentration in plasma to fall by 50%. It measures how fast a substance clears from blood — not how long its downstream biological effects last. BPC-157 half-life explained →
- GHRH (Growth Hormone-Releasing Hormone)
- A hypothalamic hormone that binds the GHRH receptor on pituitary cells, activating the cAMP pathway to stimulate growth-hormone synthesis and release. Tesamorelin and CJC-1295 are synthetic GHRH analogs. Tesamorelin mechanism →
- GHS-R1a (Ghrelin receptor)
- The receptor activated by ghrelin and ghrelin-mimetic peptides (like Ipamorelin). Signals through a separate, calcium-based pathway from GHRH, which is why combining a GHRH analog with a GHS-R1a agonist can produce a larger combined growth-hormone response. CJC-1295 + Ipamorelin synergy →
- HPLC (High-Performance Liquid Chromatography)
- The standard analytical method for measuring peptide purity. It separates a sample's components by chemical properties, and purity is calculated as the target compound's peak area divided by the total peak area. Peptide purity standards explained →
- In-vitro
- Research conducted outside a living organism — in cell culture, a test tube, or a controlled laboratory apparatus. Contrasted with in-vivo (inside a living organism).
- In-vivo
- Research conducted within a living organism, such as a rodent model. Preclinical peptide research typically progresses from in-vitro to in-vivo animal studies before any human data exists, if it exists at all.
- Incretin receptor agonist
- A class of compounds that activate gut-hormone receptors involved in metabolic regulation — GLP-1, GIP, and/or glucagon receptors. Semaglutide, tirzepatide, and retatrutide are single, dual, and triple agonists respectively. Retatrutide vs Tirzepatide vs Semaglutide →
- Lot number
- A unique identifier assigned to a specific manufacturing batch. The single most important field to verify on a COA — it must match the number printed on the vial label exactly, or the COA may belong to a different batch entirely. How to read a COA →
- Lyophilized
- Freeze-dried into a stable powder for storage and shipping. Lyophilized peptides are generally stable at room or cold temperature for extended periods and must be reconstituted with a diluent before use in solution. How to reconstitute peptides →
- Mass spectrometry (MS)
- An analytical technique that confirms a compound's molecular weight and identity, typically paired with HPLC. Purity alone doesn't confirm you have the correct compound — mass spec does. Peptide purity standards explained →
- Nonapeptide
- A peptide composed of nine amino acids. DSIP (delta sleep-inducing peptide) is a nonapeptide. What is DSIP? →
- Pentadecapeptide
- A peptide composed of fifteen amino acids. BPC-157 is a pentadecapeptide derived from a partial sequence of a protein found in gastric juice. BPC-157 vs TB-500 →
- Reconstitution
- The process of dissolving a lyophilized (freeze-dried) peptide in a liquid diluent — typically bacteriostatic or sterile water — to prepare it for use in research. How to reconstitute peptides →
- Research use only (RUO)
- A regulatory designation meaning a compound is sold strictly for laboratory and preclinical research — not for human or animal consumption, diagnosis, or treatment. Every product and article on this site is framed under this designation.
- Sequence identity / sequence-verified
- Confirmation via mass spectrometry that a peptide's amino-acid sequence exactly matches the intended compound, distinct from purity (which measures how much of the sample is the target compound, correct sequence or not).
- Tripeptide
- A peptide composed of three amino acids. GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (GHK). GHK-Cu copper peptide explained →
⚠ Definitions are provided for research and educational purposes only. All compounds referenced are for research use only and are not intended for human consumption.