Scientific Glossary
Plain-English definitions for every scientific term used in peptide research. No PhD required.
A measure of total compound exposure over time — the integral of concentration vs. time curve.
Cellular energy sensor that activates catabolic pathways and inhibits anabolic pathways when energy is low.
Cellular self-cleaning process that degrades and recycles damaged proteins and organelles.
A compound that binds to a receptor and activates it, producing a biological response.
The formation of new blood vessels from pre-existing vasculature — essential for wound healing and tissue repair.
A compound that blocks a receptor without activating it, preventing endogenous or exogenous agonists from binding.
The fundamental building blocks of peptides and proteins. Twenty standard amino acids combine in different sequences to create all biological peptides.
The fraction of an administered compound that reaches systemic circulation in active form.
Sterile water for injection containing 0.9% benzyl alcohol as a bacteriostatic preservative for multi-use vials.
Sterile water containing 0.9% benzyl alcohol, used to reconstitute lyophilized peptides for research purposes.
A selective semipermeable border that separates circulating blood from brain tissue, protecting the CNS from many compounds.
Maximum (peak) plasma concentration achieved after administration.
Laboratory document verifying the composition, purity, and potency of a research compound.
Second messenger molecule that relays signals from GPCRs to intracellular targets, regulating a wide array of cellular processes.
Most abundant protein in the body. Forms the structural scaffolding of connective tissue, skin, bone, tendons, and cartilage.
The brain and spinal cord — the primary information-processing and regulatory center of the human body.
A research administration pattern that alternates between active and washout periods to preserve receptor sensitivity and avoid tachyphylaxis.
Peptides composed of exactly two or three amino acids, respectively. Among the simplest functional peptide structures.
Reduced response to a compound following repeated or prolonged exposure, due to receptor-level changes rather than reduced compound concentration.
Testing for bacterial endotoxins (LPS) that cause fever and inflammatory responses even without live bacteria.
The non-cellular structural scaffolding that surrounds and supports cells in tissues — composed of collagens, proteoglycans, and glycoproteins.
The ranked classification of scientific evidence quality, from anecdote to systematic meta-analysis.
Focal Adhesion Kinase signaling pathway that regulates cell migration, adhesion, and survival — key mechanism for BPC-157's tissue repair effects.
Primary connective tissue cell responsible for producing collagen, elastin, and other ECM components essential for wound healing.
Incretin hormone secreted by intestinal L-cells in response to food intake. Regulates glucose homeostasis and satiety.
Incretin hormone secreted by intestinal K-cells. Potentiates insulin release and plays roles in fat storage and energy metabolism.
Hypothalamic peptide that stimulates pituitary release of growth hormone in a pulsatile pattern.
Synthetic peptides that stimulate GH secretion via ghrelin receptor pathway, independent of GHRH.
Largest receptor superfamily in the human genome. Most peptide hormones act through GPCRs.
Reduction in stomach acid production — relevant to research on gut-protective peptides and GI health.
The process by which information encoded in DNA is used to synthesize functional proteins or RNA molecules.
Hypothalamic peptide that controls reproductive hormone cascades by stimulating pituitary LH and FSH release.
The time required for the concentration of a compound in the body to reduce by half.
Analytical technique used to separate, identify, and quantify compounds in a mixture.
A blood marker reflecting average blood glucose levels over the preceding 2-3 months. Primary outcome measure in diabetes research.
A dose-response phenomenon where low doses of a stressor produce beneficial adaptive responses, while high doses are harmful.
Administration route where compounds are injected directly into muscle tissue.
Primary mediator of GH effects. Produced mainly in the liver in response to GH stimulation.
Chronic, low-grade systemic inflammation that increases with aging and drives many age-related diseases.
A standardized unit of biological activity used for hormones, vitamins, and biologics where mass alone doesn't reflect potency.
Gut hormones released in response to food intake that amplify insulin secretion in a glucose-dependent manner.
The immune system's first-line protective response to injury or infection — essential for healing but damaging when chronic.
Drug delivery via the nasal mucosa — studied for peptides requiring CNS access or rapid absorption without injection.
Neuropeptide encoded by the KISS1 gene that acts as a master regulator of reproductive hormone release via GnRH neurons.
Freeze-drying process that removes moisture from compounds under vacuum, creating stable powder form.
A dehydration preservation process that removes water from a compound under vacuum, leaving a stable dry powder.
An initial higher dose given to rapidly reach therapeutic concentrations, followed by maintenance doses to sustain those levels.
Central kinase that integrates nutrient, energy, and growth factor signals to regulate cell growth and metabolism.
The process by which cells increase their number of mitochondria in response to energy demands.
Analytical technique that identifies compounds by measuring the mass-to-charge ratio of ionized molecules with extreme precision.
A family of receptors (MC1R-MC5R) and their endogenous ligands (α-MSH, β-MSH, γ-MSH, ACTH) regulating pigmentation, sexual function, inflammation, and energy balance.
The protective lining of hollow organs (gut, respiratory tract, urogenital tract) that prevents pathogen invasion and regulates absorption.
Coenzyme found in all living cells, critical for energy metabolism, DNA repair, and cellular signaling.
Mechanisms and interventions that preserve neuronal function and prevent neuron death from injury, disease, or aging.
A gaseous signaling molecule produced by nitric oxide synthase enzymes, with roles in vasodilation, immune function, and neurotransmission.
Direct NAD+ precursor that efficiently raises intracellular NAD+ levels. Extensively studied for anti-aging, metabolic, and cognitive health research.
Unintended biological effects of a compound acting at receptors or pathways other than its primary target.
The study of how the body processes a compound — absorption, distribution, metabolism, and excretion (ADME).
The study of how a compound affects the body — its mechanisms, effects, and dose-response relationships.
The covalent bond formed between the carboxyl group of one amino acid and the amino group of another, with loss of a water molecule.
The study of what a compound does to the body — its mechanisms of action, receptor binding, and biological effects.
The sequential stages of human clinical testing required before regulatory approval, each with distinct objectives and scale.
Laboratory and animal studies conducted before human trials to establish safety, efficacy signals, and mechanistic understanding.
The enzymatic breakdown of peptides and proteins by proteases — the primary reason most peptides cannot be taken orally.
Hormonal release in discrete bursts rather than continuously — the natural pattern for many hormones including GH, GnRH, LH, and insulin.
The process of dissolving a lyophilized (freeze-dried) peptide powder into sterile liquid solution.
Reduction in receptor number or sensitivity following prolonged or excessive stimulation.
The gold standard of clinical evidence — participants are randomly assigned to treatment or control groups to minimize bias.
The process of dissolving a lyophilized (freeze-dried) peptide powder in an aqueous solution for research administration.
Administration route where the compound is injected into the fatty tissue just beneath the skin.
The condition where drug input equals drug output, maintaining consistent plasma levels.
A state of permanent cell cycle arrest that cells enter in response to stress or damage.
The degree to which a compound preferentially acts on one receptor subtype over others in the same family.
A family of NAD+-dependent deacetylase enzymes (SIRT1-7) central to aging, metabolism, DNA repair, and stress resistance.
Inhibitory peptide produced in the hypothalamus, pancreas, and gut that suppresses GH, insulin, and glucagon release.
A set of practices used to prevent microbial contamination during compound preparation and administration.
Time to reach maximum plasma concentration after administration.
Rapid, short-term reduction in response to a compound following initial administration.
Protective caps on chromosome ends that shorten with each cell division — a biological clock of cellular aging.
Gradual increase of a compound's quantity over time to minimize adverse effects while reaching target levels.
Pro-inflammatory cytokine produced primarily by macrophages. A central mediator of acute and chronic inflammation.
Primary signaling protein driving angiogenesis — the formation of new blood vessels.
A period without compound administration to allow clearance and restore receptor sensitivity before a new study phase.
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