Research Glossary

Plain-language definitions of the terms used across our product descriptions and mechanism summaries.

For Research Use Only

These products are intended for laboratory research use only and are not for human consumption. Not for use in food, drug, household, or cosmetic applications. All research should be conducted in accordance with applicable safety guidelines and regulations.

Receptors & Signaling

GHS receptor (growth hormone secretagogue receptor)
The receptor for ghrelin, found in the pituitary and hypothalamus. Compounds that activate it (ghrelin mimetics such as ipamorelin or GHRP-2) stimulate pulsatile growth hormone release in research models, which is why they are called growth hormone secretagogues.
Incretin
A gut hormone released after eating that amplifies insulin secretion. GLP-1 and GIP are the two major incretins; compounds engineered to activate their receptors (semaglutide, tirzepatide) are central tools in metabolic research.
GLP-1 (glucagon-like peptide-1)
An incretin hormone involved in glucose-dependent insulin secretion, gastric emptying, and satiety signaling. "GLP-1 receptor agonist" describes a compound that binds and activates its receptor.
GIP (glucose-dependent insulinotropic polypeptide)
The second major incretin. Dual agonists engage both the GIP and GLP-1 receptors; triple agonists add the glucagon receptor.
GHRH (growth hormone-releasing hormone)
The hypothalamic hormone that signals the pituitary to release growth hormone. GHRH analogues (sermorelin, tesamorelin, CJC-1295) act on the GHRH receptor, a distinct mechanism from the ghrelin-mimetic secretagogues.
Melanocortin receptors (MC1R–MC5R)
A receptor family involved in pigmentation, energy balance, and sexual arousal pathways. Melanotan II and PT-141 (bremelanotide) are melanocortin receptor agonists studied for their central signaling effects.
Amylin receptor (AMYR)
The receptor for amylin, a hormone co-secreted with insulin that contributes to satiety and slows gastric emptying. Cagrilintide is a long-acting amylin analogue studied alongside GLP-1 agonists.
LH/CG receptor
The shared receptor for luteinizing hormone and chorionic gonadotropin (HCG). Central to reproductive endocrinology and steroidogenesis research.

Molecular & Cellular Biology

Actin sequestration
The binding of monomeric G-actin, holding it in reserve so it cannot polymerize into filaments. Thymosin beta-4 (the parent protein of TB-500) is the major actin-sequestering peptide in cells, which is how it influences cell migration and cytoskeletal dynamics.
MMP / TIMP
Matrix metalloproteinases (MMPs) are enzymes that remodel the extracellular matrix; tissue inhibitors of metalloproteinases (TIMPs) counterbalance them. The MMP/TIMP balance appears throughout wound-healing and tissue-remodeling literature, including GHK-Cu research.
BDNF / NGF
Brain-derived neurotrophic factor and nerve growth factor — neurotrophins that support neuronal survival, growth, and synaptic plasticity. Semax research centers on upregulation of these factors.
Telomerase
The enzyme that extends telomeres, the protective caps on chromosome ends that shorten with each cell division. Epithalon research examines telomerase activation in somatic cells.
Sirtuins
A family of NAD+-dependent enzymes linked to DNA repair, metabolism, and cellular stress responses. Their dependence on NAD+ is why NAD+ levels feature prominently in cellular-aging research.
VEGF (vascular endothelial growth factor)
A signaling protein that drives angiogenesis — the formation of new blood vessels. BPC-157 literature frequently discusses VEGF pathway modulation in tissue-repair models.
Cathelicidin
A class of antimicrobial peptides of the innate immune system. LL-37 is the only human cathelicidin, studied for both direct antimicrobial activity and immune-signaling roles.
Angiogenesis
The growth of new blood vessels from existing ones — a core process in wound healing and tissue repair research.

Chemistry & Handling

Lyophilization (freeze-drying)
Removing water from a frozen solution under vacuum, leaving a stable powder. Research peptides ship lyophilized because the dry form stores far longer than a solution.
Reconstitution
Dissolving a lyophilized powder in a solvent before laboratory use. Bacteriostatic water is the common multi-dose default; the right solvent depends on the research protocol.
Bacteriostatic water
Sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and supports a refrigerated multi-use window (typically 28 days) after reconstitution.
Aliquot
A measured sub-portion of a solution. Dividing a reconstituted vial into aliquots avoids repeated freeze-thaw cycles of the whole stock.
Amino acid sequence
The ordered chain of amino acid residues that defines a peptide, written in one- or three-letter codes. Analytical identity methods provide evidence that a product matches its expected sequence.
CAS number
A unique identifier assigned to a chemical substance by the Chemical Abstracts Service. Useful for unambiguous lookup across databases and literature.
Molecular weight
The mass of one molecule, in daltons (Da) or g/mol. Mass spectrometry compares the observed mass to this expected value to confirm identity.
Elimination half-life
The time for a compound’s concentration in plasma to fall by half, as reported in pharmacokinetic literature. Listed on our product pages only where a published human value exists.
Solubility
Which solvents a compound dissolves in, and how readily. Peptide solubility varies with sequence charge and hydrophobicity.

Quality & Documentation

HPLC (high-performance liquid chromatography)
A separation technique that resolves a sample into its components. In peptide quality control, the main peak’s share of the detected chromatographic signal is reported as purity. The number is method-limited: contaminants that co-elute, respond weakly to the detector, or fall outside the method are not captured, and it does not state the total peptide content of a vial.
Mass spectrometry (MS)
Measures molecular mass with high precision. An observed mass matching the expected molecular weight supports the product’s identity — isomers or wrong sequences can share a mass, so unambiguous identity needs orthogonal evidence such as sequencing or fragmentation data.
Certificate of Analysis (CoA)
The manufacturer’s quality-control document for a specific production lot — identity, purity, and batch information. See our guide to reading one.
Lot / batch number
The identifier tying a vial to its production run and its CoA. Documentation is only meaningful when its lot number matches the vial in hand.
Research Use Only (RUO)
A regulatory designation: the product is sold exclusively for in vitro laboratory research and is not for human or veterinary use, food, drugs, or cosmetics.

Wondering how these terms come together on a quality document? See How to Read a Certificate of Analysis or our Quality Standards.