Peptide Glossary

A small-molecule NNMT inhibitor studied for metabolic and fat-cell research — not a peptide, but studied in the same programmes.

The salt form peptides are supplied as; net peptide content is slightly below the raw weight because of the counter-ion.

The protein scaffold that lets cells move, divide and repair — the target of Thymosin Beta-4 / TB-500 research.

A measured portion of a solution divided off for separate use — e.g. splitting a reconstituted vial to limit freeze-thaw cycles.

A melanocortin hormone controlling pigmentation and inflammation; the parent of peptides such as KPV and PT-141.

The building-block molecules of peptides and proteins; each contributes one residue to the chain.

The specific order of amino-acid residues in a peptide — its "primary structure" — which dictates shape and activity.

The cell’s master energy sensor; its activation is a key mechanism studied for MOTS-c and metabolic research compounds.

A sealed single-use glass container snapped open at the neck — an alternative to a stoppered multi-use vial.

A peptide deliberately modified from a natural sequence to improve stability, selectivity or potency.

The formation of new blood vessels from existing ones — central to how tissue-repair peptides are studied.

A molecule that neutralises reactive oxygen species, protecting cells from oxidative damage — e.g. glutathione.

A modified fragment of the C-terminus of growth hormone (176-191) studied for fat metabolism, separated from GH’s other effects.

Programmed cell death — an orderly self-destruct that clears damaged cells; targeted by senolytic peptide research.

Acetyl hexapeptide-8 — the best-known cosmetic "neuro-cosmetic" peptide, studied for the appearance of expression lines.

The cell’s self-cleaning recycling process; enhancing it is a recurring theme in longevity and metabolic research.

Sterile water containing 0.9% benzyl alcohol, the standard solvent for reconstituting peptides so a multi-use vial stays sterile.

The code identifying one specific production run, tying a vial to its own Certificate of Analysis and test results.

Brain-Derived Neurotrophic Factor — a protein supporting neuron survival and plasticity, central to nootropic peptide research.

A mild aromatic-alcohol preservative (typically 0.9%) that makes bacteriostatic water bacteriostatic.

How tightly a molecule binds its target receptor — a key measure of how potent and selective a compound is.

The fraction of an administered dose that actually reaches circulation intact — low for oral peptides, higher for injection.

A 15-amino-acid peptide derived from a gastric protein, studied for tendon, ligament, gut and soft-tissue repair.

Capping a peptide’s C-terminus with an amide group to mimic the natural molecule and slow enzymatic breakdown.

A mixture of low-molecular-weight neuropeptides and amino acids studied for neurotrophic and neuroprotective effects.

A batch-specific lab document reporting a compound’s identity and purity — the primary proof of what is in the vial.

A family of techniques that separate a mixture’s components by how they move through a medium — the basis of HPLC.

A synthetic GHRH analog studied for stimulating sustained, endogenous growth-hormone release, often paired with a GHRP.

A non-protein helper — a metal ion or small molecule — that an enzyme or peptide needs to be active.

Keeping temperature-sensitive peptides consistently cool from dispatch to storage to preserve integrity.

The most abundant structural protein in skin, tendon and bone — the target that skin- and repair-peptide research aims to build.

How much peptide is dissolved per unit of liquid — set by the water volume chosen at reconstitution.

A peptide complexed with a copper ion; the best-known is GHK-Cu, studied for skin remodelling and hair support.

A defined period of administration followed by a break — the on/off structure many research protocols follow.

A peptide whose chain is joined into a ring, giving greater stability and often better receptor selectivity.

Protection of cells against injury — a proposed mechanism for gut- and tissue-protective research peptides.

Amino acids come in mirror-image L and D forms; swapping in D-residues can make a peptide far more stable to enzymes.

The breakdown of a peptide into inactive fragments — by hydrolysis, oxidation or enzymes — reducing purity and potency.

A moisture-absorbing packet included with lyophilised peptides to keep the dry powder free of water during storage.

A covalent bridge between two cysteine side chains that locks a peptide’s three-dimensional shape in place.

Delta Sleep-Inducing Peptide — a nonapeptide studied for slow-wave (deep) sleep, stress resilience and circadian regulation.

The maximum effect a compound can produce once bound — distinct from potency, which is the dose needed to get there.

The stretchy structural protein that lets skin and tissues recoil — studied alongside collagen in skin-remodelling research.

Bacterial cell-wall toxins that can contaminate a preparation; low endotoxin levels are a marker of clean manufacturing.

A protein catalyst that speeds up a specific biochemical reaction — including the enzymes that build and break peptides.

A tetrapeptide (Ala-Glu-Asp-Gly) studied for telomerase activation, circadian regulation and longevity research.

The scaffold of collagen, elastin and other molecules that surrounds cells — the structural target of skin and repair research.

The skin cell that manufactures collagen, elastin and matrix — the cell that skin-signalling peptides aim to activate.

A needle with a built-in filter used to draw from an ampoule or vial, trapping glass shards or particulates.

A designed peptide (FOXO4 D-Retro-Inverso) studied as a senolytic — selectively clearing senescent "zombie" cells in ageing research.

Repeated freezing and thawing that degrades peptides; minimised by aliquoting so each portion is thawed only once.

The brain’s main calming neurotransmitter; modulating GABA signalling is part of Selank’s anxiolytic research.

A copper-binding tripeptide (Gly-His-Lys) studied for collagen synthesis, skin remodelling and hair-follicle support.

The "hunger hormone" whose receptor is the target of GHRPs, linking appetite signalling to growth-hormone release.

Growth-Hormone-Releasing Hormone — the hypothalamic hormone that signals the pituitary to release growth hormone.

Growth Hormone Releasing Peptide — a class acting on the ghrelin receptor to trigger pulsatile GH release.

A tripeptide (glutamate-cysteine-glycine) that is the body’s master antioxidant, studied for detoxification and skin.

Good Manufacturing Practice — the quality-system standard governing how materials are produced and controlled.

The pituitary hormone driving growth, repair and metabolism; the target of secretagogue rather than direct-supply research.

The time for a compound’s concentration to fall by half — a key determinant of dosing frequency in research.

A potent growth-hormone-releasing hexapeptide (GHRP) studied for strong pituitary GH release via the ghrelin receptor.

High-Performance Liquid Chromatography — the standard technique for measuring the purity of a peptide.

A mitochondrial-derived peptide studied for cytoprotection, metabolic regulation and neuroprotection in ageing research.

The water-driven breaking of a peptide bond — the main way peptides degrade in solution, and why they are supplied dry.

Whether a peptide (or its parts) is attracted to water or repelled by it — a key driver of solubility and folding.

The brain region that governs the endocrine system, releasing GHRH and somatostatin to control the pituitary.

Insulin-like Growth Factor 1 — the hormone through which much of growth hormone’s effect is actually carried out.

Adjusting the immune system up or down toward balance — the research theme behind thymic and defence peptides.

Anything in a sample that is not the intended peptide — truncated sequences, by-products, salts or solvents.

The body’s protective response to injury; calming excess inflammation is a target of gut- and repair-peptide research.

A fine-needle syringe marked in units (100 units = 1 mL) used to measure small reconstituted peptide volumes precisely.

A measure of biological activity; on a research syringe the "units" scale is a convenient volume marker, not a mass.

Into muscle tissue — a delivery route with faster absorption than subcutaneous, referenced in some research protocols.

Delivery through the nasal lining — the route some peptides such as Semax and Selank are studied via.

A selective growth-hormone secretagogue (a pentapeptide) studied for pulsatile GH release with minimal effect on other hormones.

The pH at which a peptide carries no net charge — where it is least soluble, affecting handling and purification.

A tripeptide (lysine-proline-valine) from the C-terminus of alpha-MSH, studied for anti-inflammatory and gut-calming effects.

A synthetic octapeptide studied for tightening intestinal barrier junctions ("leaky gut") and gut-related immune research.

A human cathelicidin antimicrobial peptide studied for host defence, wound healing and modulation of inflammation.

A larger initial amount used to reach a target level quickly, before settling to a smaller maintenance amount.

Freeze-dried. Peptides are supplied as a lyophilised powder/pellet for stability, then reconstituted before study.

The smaller ongoing amount that holds a compound at a target level after any initial loading phase.

An analytical method that measures a molecule’s mass to confirm a peptide’s identity matches its intended sequence.

Palmitoyl pentapeptide — a topical peptide studied for stimulating collagen and extracellular-matrix synthesis in skin.

A synthetic phenothiazine dye (not a peptide) studied for mitochondrial electron transport, cellular energy and cognition.

The cell’s energy-producing organelles; their function is central to cellular-energy and longevity research.

The mass of one mole of a compound (in g/mol or Daltons) — used to convert between milligrams and moles.

A mitochondrial-derived peptide studied for metabolic regulation, cellular energy and exercise capacity.

Capping a peptide’s N-terminus with an acetyl group to improve stability and resistance to breakdown.

The two ends of a peptide chain: the N-terminus has a free amino group, the C-terminus a free carboxyl group.

Nicotinamide adenine dinucleotide — a coenzyme central to mitochondrial energy and sirtuin activity, declining with age.

The thickness of a needle — a higher gauge number means a thinner needle; fine gauges suit subcutaneous work.

The formation of new neurons; supporting it is a proposed mechanism in cognitive and neuroprotective peptide research.

Guarding neurons against injury, stress and degeneration — the shared aim of the nootropic and neuro-recovery peptides.

Signalling proteins (like BDNF and NGF) that keep neurons alive and growing — the pathway many nootropic peptides target.

Nicotinamide mononucleotide — a direct precursor the body converts into NAD+, studied for cellular energy and longevity.

A substance studied for supporting cognition — focus, memory, clarity — often via neurotrophic or neuroprotective pathways.

Cellular damage from an excess of reactive oxygen species — the imbalance antioxidants and many longevity compounds target.

Very short peptides proposed to act tissue-specifically on gene expression — the basis of the longevity bioregulator research.

The covalent amide bond linking amino acids into a peptide chain — the defining structural feature of every peptide.

A tripeptide (Glu-Asp-Arg) peptide bioregulator studied for neuroprotection, cognition and sleep.

The "master gland" at the base of the brain that releases growth hormone and other hormones on hypothalamic command.

A single continuous chain of many amino acids linked by peptide bonds — the backbone of both long peptides and proteins.

The amount of a compound needed to produce a given effect — a more potent compound works at a lower dose.

Enzymes that cut peptide bonds; proteolysis is the enzymatic breakdown that limits most peptides’ half-life.

A large biological molecule of one or more long amino-acid chains; peptides are the same chemistry at shorter length.

Bremelanotide — a melanocortin-receptor agonist studied for sexual arousal and libido via central nervous-system pathways.

The percentage of a sample that is the intended peptide, as measured by HPLC — the headline quality figure.

A receptor is a cell’s signal-receiving protein; an agonist binds it and activates it, an antagonist blocks it.

The process of dissolving a lyophilised (freeze-dried) peptide in a sterile solvent such as bacteriostatic water before study.

A highly characterised sample of known identity and purity used to calibrate tests and confirm what a batch contains.

A designation that a compound is supplied strictly for laboratory research and is not intended for human or veterinary use.

The levels of peptide/protein organisation: sequence (primary), local folds (secondary), 3-D shape (tertiary), assembly (quaternary).

A substance that prompts a gland to secrete a hormone — e.g. a GH secretagogue triggers the pituitary to release growth hormone.

A synthetic heptapeptide analog of tuftsin studied for anxiolytic (calming) and immunomodulatory effects.

How specifically a compound acts on its intended target and few others — the basis of a "clean" research effect.

A synthetic analog of a fragment of ACTH, studied for neuroprotection, focus and cognitive performance.

A GHRH(1-29) fragment — the shortest sequence of GHRH that retains activity — studied for endogenous growth-hormone release.

How long a product stays within specification under proper storage — longest lyophilised and frozen, shortest once reconstituted.

The variable "R group" on each amino acid that gives it its chemical character — charge, size and water-affinity.

A family of NAD+-dependent enzymes tied to ageing, DNA repair and metabolism — central to NAD+ longevity research.

Acetyl octapeptide-3 — a topical cosmetic peptide studied for the appearance of expression lines by modulating muscle-nerve signalling.

The hypothalamic hormone that inhibits growth-hormone release — the "off switch" opposing GHRH.

A mitochondria-targeting tetrapeptide (elamipretide) studied for protecting the inner mitochondrial membrane and cellular energy.

How well a peptide resists degradation over time under given conditions — the property that dictates storage and handling.

The practice of avoiding contamination when reconstituting and drawing from vials — wiping stoppers, single-use needles.

Freedom from viable micro-organisms; sterility testing confirms a preparation is not contaminated by bacteria or fungi.

Into the layer of fat just beneath the skin — the route most peptide research protocols reference.

A synthetic fragment analog of Thymosin Beta-4, studied for cell migration, full-body tissue repair and flexibility.

Protective caps on chromosome ends (telomeres) and the enzyme that extends them (telomerase) — central to longevity research.

A stabilised GHRH analog studied for stimulating endogenous growth-hormone release, notably in visceral-fat research.

Independent laboratory verification of identity and purity — testing not done by the seller, for unbiased confidence.

A thymus-gland peptide bioregulator studied for immune regulation and restoration of balanced immune function.

A family of thymus-associated peptides; Thymosin Beta-4 underlies TB-500’s tissue-repair research.

Thymosin Alpha-1 (Tα1) — a thymus-derived peptide studied for immune modulation and T-cell function.

Gradually adjusting an amount — usually starting low and increasing — to find a suitable level in a research protocol.

Applied to the surface of the skin — the route studied for cosmetic peptides such as GHK-Cu, Argireline and Matrixyl.

Short peptides named for their residue count — three (tri), four (tetra), five (penta) amino acids.

The small sealed glass container, capped with a rubber stopper, that peptides are supplied and reconstituted in.

Vasoactive Intestinal Peptide — a 28-residue signalling peptide studied for anti-inflammatory, immune and neuroprotective effects.