Reference
Peptide Research Glossary
Plain-language definitions of terms researchers run into when working with peptides. Use this as a quick reference alongside the Research Library.
A
- AMPK
- AMP-activated protein kinase — a master regulator of cellular energy metabolism. Activation is associated with increased fat oxidation and reduced anabolic activity.
B
- BPC-157
- Body Protection Compound-157, a synthetic peptide derived from a gastric protein; widely studied in animal models for tissue repair and gastrointestinal protection. View BPC-157 research →
C
- COA
- Certificate of Analysis — a document issued by a laboratory certifying the identity, purity, and properties of a specific batch of material. Keystone publishes a COA for every batch.
D
- DOI
- Digital Object Identifier — a persistent identifier used to cite scientific papers. DOIs resolve to the publisher’s landing page for the article.
E
- Epithalon
- A short synthetic tetrapeptide studied for effects on telomerase activity, sleep, and circadian rhythm. View Epithalon research →
F
- FDA
- U.S. Food and Drug Administration. Keystone Research Supply products are not FDA-evaluated and not for human or veterinary use.
G
- GHK-Cu
- A copper-binding tripeptide studied for skin and wound-repair endpoints in vitro.
- GHRH
- Growth-hormone-releasing hormone — a hypothalamic peptide that triggers pituitary release of growth hormone. Synthetic analogs are used in research models.
- GLP-1
- Glucagon-like peptide-1 — an incretin that stimulates insulin secretion. GLP-1 receptor agonists (semaglutide, liraglutide) are studied for metabolic endpoints.
- GLP-2
- Glucagon-like peptide-2 — an intestinotrophic hormone studied for gut-mucosa endpoints.
I
- IGF-1
- Insulin-like growth factor-1 — a mediator of growth-hormone effects on tissue growth and metabolism.
- In vitro
- Latin: “in glass.” Refers to experiments performed outside a living organism — typically in cell cultures or biochemical assays.
- In vivo
- Latin: “within the living.” Refers to experiments performed in whole organisms such as model animals.
L
- Lyophilized
- Freeze-dried. Peptides are commonly lyophilized to extend stability and shelf life. Reconstitution is required prior to research use.
M
- MOTS-c
- A mitochondrial-derived peptide studied for metabolic regulation in research models. View MOTS-c research →
N
- NAD+
- Nicotinamide adenine dinucleotide (oxidized form) — a coenzyme central to cellular redox metabolism.
P
- PEG
- Polyethylene glycol — a polymer attached (PEGylated) to therapeutic peptides to increase circulation half-life in research models.
- Peptide
- A short chain of amino acids linked by peptide bonds. Typically distinguished from proteins by length (fewer than ~50 residues).
- Pharmacodynamics (PD)
- The study of what a substance does to the body — receptor binding, downstream signaling, and dose-response relationships.
- Pharmacokinetics (PK)
- The study of how a substance moves through the body — absorption, distribution, metabolism, and excretion.
- PMID
- PubMed Identifier — the unique numeric identifier assigned by PubMed to indexed biomedical articles. Used in citations on this site.
- Purity
- The percentage of a sample that is the intended chemical compound, typically determined by HPLC and reported on the Certificate of Analysis.
R
- Reconstitution
- The process of dissolving a lyophilized (freeze-dried) peptide in a sterile diluent such as bacteriostatic water prior to research use.
- RUO
- Research Use Only. Materials sold strictly for in vitro and laboratory research. Not drugs, supplements, food, or cosmetics. Not for human or veterinary use. View Compliance & RUO Policy →
S
- Semaglutide
- A long-acting GLP-1 receptor agonist studied for metabolic endpoints. Sold by Keystone for research use only. View Semaglutide research →
- SS-31
- A mitochondria-targeted tetrapeptide studied for cardiolipin binding and mitochondrial function in research models. View SS-31 research →
- Subcutaneous
- Beneath the skin. A common route of administration in preclinical animal research models. Not applicable to RUO laboratory use.
T
- Tirzepatide
- A dual GIP/GLP-1 receptor agonist studied for metabolic endpoints. View Tirzepatide research →