Skip to main content
RUO Free USPS Priority shipping over $200 — same-day USA dispatch.
Cart 0
Buy Peptides — Obesity & Metabolic — Mitochondria & Energy — Healing & Recovery — Cognitive & Nootropic — Growth & Anti-Aging — Cosmetic — Sexual Health — Blends About Knowledge Center Blog Bulk Orders Contact Call View cart

Knowledge

Peptide & biochemistry glossary

A–Z reference of terms researchers encounter on COAs, in protocols, and in the peptide literature.

A

Acetate counterion
A small acetate ion that pairs with positively charged peptide residues in the lyophilized salt form. Most research peptides are shipped as acetate salts.
Aliquot
A single-use sub-portion of a reconstituted peptide solution, transferred into its own vial to avoid repeated freeze/thaw cycles.
Amino acid
The building block of peptides and proteins. The 20 canonical amino acids are denoted by 1-letter (A, G, R…) or 3-letter (Ala, Gly, Arg…) codes.
Analog
A molecule structurally similar to a parent compound but with one or more deliberate sequence or chemistry modifications.

B

BAC
Short for bacteriostatic — see BAC water.
BPC-157
A 15-amino-acid synthetic peptide derived from human gastric juice protein BPC. Studied extensively for tissue-repair models.
Bacteriostatic water (BAC water)
Sterile water containing 0.9% benzyl alcohol as a preservative. The most common general-purpose reconstitution solvent for research peptides.

C

CAS number
A unique numerical identifier assigned by the Chemical Abstracts Service to every chemical substance described in the literature.
CJC-1295
A modified GHRH analog. The DAC variant attaches a drug affinity complex extending the half-life from minutes to days.
COA
Certificate of Analysis — the document linking a specific lot to its identity (mass spec) and purity (HPLC) data.
Cathepsin
A class of proteolytic enzymes; relevant when designing in-vitro stability studies.
Cyclic peptide
A peptide whose backbone is closed into a ring, often via disulfide bond or head-to-tail amide bond.

D

DAC
Drug Affinity Complex — a maleimidopropionic acid moiety that binds covalently to serum albumin, dramatically extending plasma half-life.
DMSO
Dimethyl sulfoxide — a polar aprotic solvent used to dissolve poorly water-soluble peptides for in-vitro work.
Deamidation
Loss of an amide group from asparagine or glutamine residues, the most common in-solution degradation pathway.
Disulfide bond
A covalent S–S bond between two cysteine residues, often required for structural integrity.

E

Ester bond
A common cleavable linker chemistry in conjugated peptides.

F

Fmoc
Fluorenylmethyloxycarbonyl — the standard protecting group used in solid-phase peptide synthesis.

G

GHK-Cu
A copper-bound tripeptide (Gly-His-Lys) studied in cosmetic-research models for skin and hair.
GHRH
Growth Hormone Releasing Hormone — a 44-amino-acid hypothalamic hormone. Several research peptides (Sermorelin, CJC-1295, Mod GRF 1-29) are GHRH analogs.
GHRP
Growth Hormone Releasing Peptide — a class of synthetic ghrelin-receptor agonists (GHRP-2, GHRP-6, Ipamorelin, Hexarelin).

H

HPLC
High-Performance Liquid Chromatography — the analytical method used to measure peptide purity by integrating peak area.
Half-life (t½)
The time required for a biological signal or measured concentration to fall by 50%.

I

Ipamorelin
A pentapeptide GHRP studied as a selective GH secretagogue with minimal cortisol or prolactin signaling in cell models.

L

Lyophilization
Freeze-drying — the controlled removal of water from a frozen peptide solution under vacuum, producing the stable lyophilized cake.

M

Mass spectrometry (MS)
An analytical method that ionizes molecules and measures their mass-to-charge ratio, used to confirm peptide identity by molecular weight.
Mimetic
A molecule designed to mimic the activity of a natural ligand at its receptor.
Mod GRF 1-29
A modified, tetra-substituted version of the first 29 amino acids of GHRH. Stabilized against rapid proteolysis vs. native GHRH.
Molecular weight (MW)
The sum of atomic weights of all atoms in a molecule, expressed in Daltons (Da).
Monoisotopic mass
The exact mass calculated from the most abundant isotope of each constituent atom; the value reported by high-resolution MS.

O

Oxidation
A common in-solution degradation pathway, especially for methionine and cysteine residues.

P

PT-141 (Bremelanotide)
A cyclic heptapeptide melanocortin-receptor agonist studied in sexual-behavior research models.
Peptide
A short chain of amino acids (typically <50 residues) joined by amide (peptide) bonds.
Pharmacokinetics (PK)
The study of how a molecule is absorbed, distributed, metabolized and eliminated in a biological system.
Purity (%)
The fraction of total chromatographic signal attributable to the target peak, integrated by HPLC.

R

Recombinant
Produced by inserting a synthetic gene into a host organism (typically E. coli or yeast) which expresses the peptide as a protein.
Reconstitution
The act of dissolving a lyophilized peptide back into solution with a chosen solvent.
Research Use Only (RUO)
A regulatory designation indicating a product is sold strictly for in-vitro laboratory or research applications and is not approved for human, veterinary, or therapeutic use.
Retest date
The date by which we recommend re-running QC on a stored lot to confirm it still meets specification.

S

Salt form
The counterion paired with a charged peptide — typically acetate, hydrochloride, or trifluoroacetate (TFA).
Secretagogue
A substance that promotes secretion of another, e.g. GH secretagogue.
Selank
A synthetic heptapeptide analog of tuftsin, studied as a nootropic / anxiolytic in research models.
Semax
A synthetic ACTH(4-7) analog, studied as a nootropic in research models.
Sequence
The ordered list of amino acids that defines a peptide, written N-terminus → C-terminus.
Sermorelin
A 29-amino-acid GHRH analog corresponding to GHRH(1-29).
Solid-Phase Peptide Synthesis (SPPS)
The standard chemistry method for synthesizing peptides; amino acids are added one at a time to a resin-bound growing chain.
Solubility
The maximum amount of a peptide that will dissolve in a given solvent at a given temperature.
Stability
The persistence of a peptide's identity, purity and potency over time under defined storage conditions.

T

TB-500
A 17-mer synthetic fragment of thymosin beta-4, studied in tissue-repair models.
TFA
Trifluoroacetic acid — a common HPLC mobile-phase additive and a frequent counterion in peptide salt forms.
Tesamorelin
A trans-3-hexenoyl GHRH(1-44) analog with extended in-vivo half-life.
Truncation
A synthesis byproduct in which one or more amino acids failed to couple, producing a shorter chain.