Peptide Glossary

A neurotransmitter responsible for muscle contraction, memory, and attention. Peptides like botulinum toxin block acetylcholine release at the neuromuscular junction, making it a critical target in neurotoxicology research. Essential for understanding neural and muscular function in peptide studies.
Related: Neuromuscular junction, SNARE proteins, Botulinum toxin

A 39-amino-acid peptide hormone produced by the anterior pituitary gland that stimulates cortisol release from the adrenal cortex. Used in research investigating stress response, HPA axis function, and adrenal pathways. Often studied in relation to immune modulation and metabolic regulation.
Related: Cortisol, HPA axis, Endocrinology

A member of the TGF-β superfamily of signalling peptides that regulates cell differentiation, proliferation, and apoptosis. Antagonised by follistatin in muscle growth research. Critical for understanding myostatin inhibition and muscle biology.
Related: Follistatin, Myostatin, TGF-β pathway

A structural protein that forms thin filaments in muscle cells. Thymosin Beta-4 (TB500) binds and sequesters actin, facilitating tissue healing and angiogenesis. Essential for understanding muscle contraction and tissue repair mechanisms.
Related: Thymosin Beta-4, Muscle contraction, Tissue repair

Body fat composed primarily of adipocytes (fat cells). Target tissue for lipolytic peptides like AOD 9604 and GHK-Cu research. Important in studying metabolic peptides and body composition research.
Related: Lipolysis, Adipocytes, GLP-1

A molecule (including peptides) that binds to a receptor and activates it, triggering a biological response. Most research peptides are agonists — GLP-1 agonists, ghrelin agonists, etc. Opposite of antagonist.
Related: Receptor, Antagonist, Signal transduction

A nucleoside that activates AMPK (AMP-activated protein kinase), mimicking the cellular energy stress response. Used in research investigating metabolic health, mitochondrial function, and exercise mimetics. Often studied alongside NAD+ and metabolic peptides.
Related: AMPK, NAD+, Mitochondrial biogenesis

The building block of proteins and peptides. 20 standard amino acids form the basis of all peptide sequences. Understanding amino acid composition is critical to peptide structure, function, and research applications.
Related: Protein, Peptide bond, Molecular formula

A cellular energy sensor enzyme activated by low energy states. Target of research peptides like MOTS-C, SS-31, and AICAR. Critical for understanding metabolic regulation, longevity, and mitochondrial function.
Related: Mitochondrial biogenesis, Metabolic pathway, NAD+

The formation of new blood vessels from existing vasculature. BPC-157, TB500, and GHK-Cu are frequently studied for their pro-angiogenic properties. Essential in tissue repair and wound healing research.
Related: Vascular endothelial growth factor (VEGF), Wound healing, Tissue repair

A molecule that binds to a receptor but does NOT activate it, blocking normal signalling. Opposite of agonist. Some peptides function as antagonists in specific pathways.
Related: Agonist, Receptor, Signal transduction

A class of peptides specifically researched for their potential longevity and senescence-delaying properties. Includes epithalon, NAD+, follistatin, and semax. Focus of rapidly growing research field.
Related: Telomerase, Senescence, Longevity

Programmed cell death. Some peptides like PNC-27 are researched for their pro-apoptotic effects in cancer cell biology. Important in understanding both normal cell turnover and therapeutic applications.
Related: Cell death, Autophagy, Cellular senescence

An amino acid and precursor to nitric oxide, a critical signalling molecule. Appears in many research peptides. Dietary supplementation sometimes combined with peptide research.
Related: Amino acid, Nitric oxide, Cardiovascular function

Sterile water containing 0.9% benzyl alcohol as a preservative. Standard solvent for reconstituting lyophilised peptides, preventing bacterial contamination. Essential for safe peptide preparation in research settings.
Related: Reconstitution, Sterile technique, Lyophilised powder

A neurotrophin that supports neuronal survival, growth, and plasticity. Upregulated by peptides like semax and selank. Critical target in neuroprotection and cognitive enhancement research.
Related: Neurotrophins, Neuroplasticity, Neuropeptides

A preservative added to bacteriostatic water (0.9%) to prevent microbial growth. Required for safe peptide reconstitution and storage. Important for understanding contamination prevention.
Related: Bacteriostatic water, Reconstitution, Sterilisation

The degree and rate at which a substance becomes available to tissues after administration. Critical consideration in peptide delivery research, as peptides are often poorly orally bioavailable compared to other routes.
Related: Pharmacokinetics, Delivery route, Absorption

A class of short peptide sequences (typically 2–4 amino acids) derived from animal organ tissues that regulate specific organ functions. Examples: Bronchogen (lung), Cardiogen (heart), Cortagen (adrenal). Designed to restore tissue-specific function.
Related: Organ-specific peptides, Tissue engineering, Peptide therapy

An extremely potent neurotoxin produced by Clostridium botulinum that cleaves SNARE proteins, preventing acetylcholine release. Studied in neuromuscular research, toxicology, and muscle contraction models. Measured in International Units (IU).
Related: SNARE proteins, Neuromuscular junction, Acetylcholine

A 15-amino-acid peptide derived from gastric juice with extensive research applications in wound healing, gut protection, angiogenesis, and anti-inflammatory effects. One of the most studied peptides in regenerative research.
Related: Tissue repair, Angiogenesis, Gut health

A unique identifier assigned to chemical compounds, including peptides. Example: Tirzepatide CAS 2023788-19-2. Essential for verifying peptide identity and purity in research.
Related: Molecular formula, Identification, Specification

The metabolic breakdown of molecules to release energy. Contrast with anabolism (building up). Understanding both is critical in metabolic peptide research.
Related: Metabolism, Anabolism, Energy production

The increase in cell number through mitosis. Many research peptides target growth factors (IGF-1, HGF, FGF) that promote proliferation. Key endpoint in cell biology research.
Related: Growth factors, Mitosis, Cell cycle

The directed movement of cells toward or away from chemical signals. Some peptides influence immune cell chemotaxis, important in immune modulation research.
Related: Immune response, Cell migration, Signalling molecules

The splitting of chemical bonds, particularly peptide bonds. Botulinum toxin cleaves SNARE proteins; proteases cleave peptide bonds during digestion. Important concept in understanding peptide degradation and mechanism of action.
Related: Peptide bond, Protease, Degradation

A structural protein in connective tissue, skin, and bone. Many peptides (GHK-Cu, Matrixyl, PAL-GHK) target collagen synthesis, making it central to anti-ageing and tissue repair research.
Related: Extracellular matrix, Skin health, Anti-ageing

The amount of peptide per unit volume (e.g., mg/mL). Critical parameter in dosing and stability research. Measured and reported in research protocols.
Related: Molarity, Molality, Dosing

A glucocorticoid hormone released by the adrenal cortex in response to ACTH. Regulated via the HPA axis. Target of stress-response peptide research.
Related: ACTH, HPA axis, Stress response

A third-party testing document confirming a peptide batch’s identity, purity, and specifications (molecular formula, molecular weight, CAS number, appearance, etc.). Essential trust signal and quality verification document.
Related: Third-party testing, Purity, Quality control

Peptides where the C-terminus and N-terminus are connected, forming a ring structure. Often more stable than linear peptides. Important distinction in peptide chemistry.
Related: Linear peptides, Stability, Structure

The breakdown of peptides by proteases over time. Affects shelf life and requires proper storage (freezing, desiccation). Critical for understanding peptide stability.
Related: Stability, Storage, Shelf life

The decreased responsiveness of a receptor to repeated or continuous exposure to its ligand (agonist). Important consideration in peptide research and dosing protocols.
Related: Tolerance, Receptor regulation, Signal transduction

A steroid hormone often studied alongside peptide research in anti-ageing contexts. Precursor to testosterone and oestrogen. Sometimes used as a comparative reference in longevity studies.
Related: Steroid hormones, Anti-ageing, Hormonal balance

The association of two molecules (peptides or proteins) to form a complex. Some peptides function as active dimers. Important structural consideration.
Related: Protein interaction, Complex formation, Structure

A covalent bond between two cysteine amino acids, stabilising peptide structure. More stable than other peptide bonds. Important for understanding peptide stability and structure.
Related: Cysteine, Peptide bond, Stability

A neurotransmitter involved in motivation, reward, and motor control. Some neuropeptides modulate dopaminergic pathways. Important in understanding neurological peptide effects.
Related: Neurotransmitter, Motivation, Motor control

The relationship between peptide concentration and biological effect. Used to establish optimal dosing, EC50 (half-maximal effective concentration), and potency. Critical for research protocol design.
Related: Potency, EC50, Efficacy

The administration of a measured amount of peptide. In research contexts, dosing is typically calculated per kilogram of body weight (mg/kg) or as absolute doses. Always conducted under controlled research protocols.
Related: Concentration, Protocol, Administration route

A 9-amino-acid neuropeptide that modulates sleep, stress, and immune function. Studied in neuroendocrine research and sleep biology. Named for its sleep-inducing properties in early research.
Related: Sleep, Neuroendocrinology, Stress response

The concentration of a drug or peptide at which 50% of the maximum biological effect is observed. Lower EC50 indicates higher potency. Critical metric in pharmacology research.
Related: Potency, Efficacy, Dose–response curve

The maximum effect a peptide can produce, regardless of dose. Distinct from potency (which relates to dosage required). Both are important for understanding peptide activity.
Related: Potency, Effect size, Pharmacology

A receptor tyrosine kinase involved in cell proliferation and survival. Some peptides modulate EGFR signalling. Important in cancer research and cell biology.
Related: Growth factor receptor, Signal transduction, Cell proliferation

The system of glands and hormones regulating body functions. Many research peptides target endocrine pathways (HPA axis, HPG axis, etc.). Fundamental to understanding hormonal peptide effects.
Related: Hormones, Glands, Signalling pathways

The cellular process of internalising molecules by enclosing them in a vesicle. Some peptides enter cells via endocytosis. Important mechanism for understanding cellular uptake.
Related: Cell uptake, Internalisation, Transport

Cells lining blood vessels. Pro-angiogenic peptides like BPC-157 target endothelial cells to promote new vessel formation. Critical in vascular research.
Related: Angiogenesis, Vasculature, Blood vessels

A 4-amino-acid peptide (Ala-Glu-Asp-Gly) derived from pineal gland extract. Researched for telomerase activation and anti-ageing properties. One of the oldest documented bioregulator peptides.
Related: Telomerase, Anti-ageing, Longevity

The network of proteins and carbohydrates surrounding cells, providing structure and signalling. Many peptides target ECM remodelling, including collagen-promoting peptides.
Related: Collagen, Tissue structure, Fibrosis

A family of growth factors promoting cell proliferation, differentiation, and angiogenesis. Some peptides modulate FGF signalling. Important in tissue repair and development research.
Related: Growth factors, Cell proliferation, Tissue repair

Cells responsible for producing collagen and extracellular matrix proteins. Target cells for anti-ageing and tissue repair peptides. Central to dermatological and regenerative research.
Related: Collagen, ECM, Skin health

Excessive accumulation of fibrous connective tissue, often pathological. Some peptides (like BPC-157) are studied for anti-fibrotic properties. Important in organ damage research.
Related: Scar tissue, Collagen deposition, Tissue damage

A 288-amino-acid binding protein that inhibits myostatin and activins, promoting muscle growth. Among the most potent natural myostatin inhibitors. Extensively researched in muscle biology and sarcopenia models.
Related: Myostatin inhibition, Muscle growth, Activin

A gonadotropin hormone regulating reproductive function. Target of GnRH (gonadotropin-releasing hormone) agonist research. Important in reproductive endocrinology studies.
Related: GnRH, Gonadotropins, Reproductive system

Negative regulator of muscle growth. Inhibition of GDF-8/myostatin is a major research target for muscle-building peptides. Critical concept in muscle biology.
Related: Myostatin, Muscle growth, ActRIIB signalling

The process by which information from a gene is transcribed into RNA and translated into proteins. Many peptides alter gene expression patterns (upregulating BDNF, telomerase, etc.). Fundamental to understanding molecular mechanisms.
Related: Transcription, Translation, Protein synthesis

A tripeptide-copper complex (Gly-His-Lys chelated to Cu2+) with extensive research in wound healing, collagen synthesis, and anti-ageing. One of the most studied cosmetic peptides in research.
Related: Copper chelation, Collagen synthesis, Skin repair

A hypothalamic peptide hormone that stimulates GH release from the pituitary. Target of GH secretagogue research (Sermorelin, CJC-1295, etc.). Central to growth hormone axis research.
Related: Growth hormone, Pituitary, GH secretagogues

A synthetic peptide class that stimulates GH release via the ghrelin receptor (distinct from GHRH pathway). Includes GHRP-2 and GHRP-6. Used to study pituitary function and growth hormone secretion.
Related: Growth hormone, Ghrelin receptor, GH secretagogues

An orexigenic peptide hormone promoting appetite and GH secretion. Receptor target for GHRP peptides and hexarelin. Important in metabolic and appetite research.
Related: Appetite regulation, GH secretion, Energy homeostasis

A 30-amino-acid incretin hormone regulating blood glucose, insulin secretion, and satiety. GLP-1 receptor agonists (semaglutide, tirzepatide) are among the most researched peptides globally. Critical in metabolic and obesity research.
Related: Incretin, Glucose homeostasis, Insulin

A class of peptide drugs/research compounds that activate the GLP-1 receptor. Includes semaglutide, tirzepatide, retatrutide, and liraglutide analogues. Dominant research peptide category.
Related: GLP-1, Receptor agonism, Metabolic research

A peptide hormone that increases blood glucose and is activated by low glucose. Part of glucose homeostasis alongside GLP-1. Dual GLP-1/glucagon agonists (mazdutide, suruvodutide) are active research area.
Related: GLP-1, Glucose homeostasis, Metabolic regulation

The maintenance of stable blood glucose levels through hormonal regulation (insulin, glucagon, GLP-1). Central target of metabolic peptide research.
Related: Insulin, Glucagon, GLP-1, Metabolism

A tripeptide antioxidant (Gly-Cys-Glu) crucial for cellular detoxification and redox balance. Researched for antioxidant and cellular protection properties. Important in cellular health research.
Related: Antioxidant, Redox balance, Cellular protection

A 10-amino-acid hypothalamic peptide controlling FSH and LH release. Target of reproductive endocrinology research. GnRH agonists and antagonists are important research compounds.
Related: Reproductive endocrinology, FSH, LH

The simplest amino acid, a building block in many peptides including collagen and glutathione. Often used in structural positions due to its small size and flexibility.
Related: Amino acid, Collagen structure

A GnRH peptide used in research to stimulate FSH and LH release. Available as gonadorelin acetate. Important in reproductive research and HPA axis studies.
Related: GnRH, Gonadotropins, Reproductive system

The time required for a peptide’s concentration to decrease to 50% of its initial value. Critical pharmacokinetic parameter determining dosing frequency and duration of effect. Varies greatly by route of administration and peptide structure.
Related: Pharmacokinetics, Stability, Elimination

A glycoprotein hormone produced during pregnancy and used in research to stimulate testosterone production. Frequently studied in hormonal research contexts. Available in 5,000 IU and 10,000 IU doses.
Related: Gonadotropin, Testosterone, Reproductive hormones

An E3 ubiquitin ligase that negatively regulates the p53 tumour suppressor. Target of PNC-27 anticancer peptide research. Important in cancer cell biology research.
Related: p53, Tumour suppression, Cell apoptosis

Molecular chaperones that help proteins fold correctly and survive stress. Some peptides upregulate HSP expression. Important in cellular stress response research.
Related: Protein folding, Cellular stress, Chaperones

A growth factor promoting cell proliferation, angiogenesis, and tissue repair. Target of peptide research aimed at tissue regeneration. Also called scatter factor.
Related: Growth factors, Angiogenesis, Tissue repair

A 191-amino-acid peptide hormone produced by the anterior pituitary that regulates growth, metabolism, and body composition. Extensively researched. The 191AA form is the natural human sequence.
Related: Growth hormone, Somatotropin, Metabolism

A 16-amino-acid C-terminal fragment of HGH with lipolytic (fat-burning) activity distinct from full-length HGH. Studied for selective metabolic and body composition effects.
Related: HGH, Lipolysis, Metabolic peptides

The analytical technique used to test peptide purity, separating components by their interaction with a liquid mobile phase. Standard method for verifying peptide quality and reported in COAs.
Related: Purity testing, Quality control, COA

The endocrine regulatory system controlling reproductive hormones. GnRH, gonadotropins (FSH, LH), and sex steroids are key components. Important in reproductive peptide research.
Related: Reproductive hormones, GnRH, Gonadotropins

The endocrine regulatory system controlling stress response and cortisol release. ACTH and CRH are key components. Central to understanding stress-response peptide effects.
Related: Cortisol, ACTH, Stress response

Hydrophobic = water-repelling (lipid-soluble). Hydrophilic = water-loving (polar). Peptide properties affect solubility, delivery, and cellular uptake. Important consideration in peptide chemistry and formulation.
Related: Solubility, Peptide structure, Absorption

Increase in cell or tissue size, often referring to muscle growth. Goal of anabolic peptide research. Distinct from hyperplasia (increase in cell number).
Related: Muscle growth, Cell enlargement

The part of the brain controlling the pituitary gland and nervous system. Produces releasing hormones (GnRH, GHRH, CRH) central to multiple peptide research axes.
Related: Pituitary, Hormonal control, CNS

A 70-amino-acid peptide hormone with anabolic effects on muscle, bone, and metabolic tissues. Promoter of cell proliferation and differentiation. One of the most studied growth factors in research.
Related: Growth factors, Muscle growth, Metabolism

A modified IGF-1 analogue with extended half-life and enhanced potency. Extensively researched for muscle growth and metabolic effects. More commonly available than natural IGF-1 for research.
Related: IGF-1, Growth factors, Muscle growth

A truncated IGF-1 variant lacking the first three amino acids. Retains biological activity while potentially having different tissue distribution. Used in regenerative research.
Related: IGF-1, Growth factors, Tissue repair

Alteration of immune function, either enhancement or suppression. Many peptides (thymosin, selank, epithalon) modulate immune responses. Critical in immunology research.
Related: Immune system, T-cells, Immune tolerance

The body’s response to injury or infection involving immune cell activation and cytokine release. Anti-inflammatory peptides (BPC-157, KPV) target this pathway. Central to tissue repair research.
Related: Cytokines, Immune response, Anti-inflammatory

The non-specific, rapid immune response involving macrophages, neutrophils, and complement. Distinguished from adaptive immunity. Some peptides enhance innate immune function.
Related: Immune system, Macrophages, Immune response

A 51-amino-acid peptide hormone regulating glucose uptake and metabolism. GLP-1 agonists enhance insulin secretion. Central to glucose homeostasis and metabolic research.
Related: Glucose, Metabolism, Pancreatic function

The responsiveness of cells to insulin signalling. GLP-1 agonists enhance insulin sensitivity. Key metric in metabolic research and obesity models.
Related: Insulin signalling, Metabolic health, Glucose uptake

A pentapeptide GH secretagogue with selectivity for ghrelin receptor over other growth hormone-releasing pathways. Extensively researched for anabolic and growth-promoting effects.
Related: GH secretagogues, Growth hormone, Ghrelin receptor

A standardised unit of measurement for biological activity, often used for hormones and immunological products (HCG, HMG, botulinum toxin). 1 IU varies by substance based on biological potency.
Related: Dosing, Standardisation, Measurement

A signalling cascade where JAK kinases phosphorylate STAT proteins, activating gene transcription. Some peptides modulate this pathway. Important in cell communication research.
Related: Signal transduction, Gene expression, Cell signalling

A neuropeptide family regulating GnRH secretion and reproductive function. Studied in pubertal and reproductive endocrinology research. Critical for understanding HPG axis activation.
Related: GnRH, Reproductive endocrinology, Puberty

A tripeptide (C-terminal fragment of alpha-MSH) with anti-inflammatory properties. Studied for skin healing and gut protection effects. Simple, short-chain structure.
Related: Alpha-MSH, Anti-inflammatory, Skin healing

An organic acid produced during anaerobic exercise. Sometimes accumulated in peptide solutions; important to note on COAs as a degradation marker or contaminant.
Related: Metabolism, Exercise physiology, Fermentation

An antimicrobial peptide derived from human cathelicidin. Researched for immune modulation, wound healing, and anti-bacterial properties. Part of innate immune defences.
Related: Antimicrobial peptides, Immune function, Wound healing

The breakdown of lipids (fats). Lipolytic peptides like AOD 9604 and GHK-Cu promote fat mobilisation. Target of metabolic and body composition research.
Related: Fat metabolism, Adipose tissue, Metabolic peptides

The process of removing water from a frozen peptide solution under vacuum, resulting in a stable powder. Standard form for most research peptides. Preserves peptide integrity better than liquid form.
Related: Freeze-drying, Powder form, Stability

The solid product of lyophilisation — a light, dry powder that requires reconstitution with bacteriostatic water or acetic acid before use. Standard delivery form for research peptides.
Related: Lyophilisation, Reconstitution, Stability

Large immune cells that engulf pathogens and debris. Some peptides enhance macrophage function. Important in innate immunity and inflammation research.
Related: Immune cells, Innate immunity, Inflammation

A pentapeptide derivative targeting collagen synthesis and skin remodelling. Extensively researched in cosmetic peptide applications. Also called Pal-KTTKS.
Related: Collagen synthesis, Anti-ageing, Skin health

The biochemical pathway or process by which a peptide produces its effect. Understanding MOA is critical to research design and interpreting results.
Related: Pharmacology, Signal transduction, Biological effect

The pigment responsible for skin colour. Melanocortin receptor agonists (MT-1, MT-2, PT-141) stimulate melanin production. Target in tanning and pigmentation research.
Related: Melanocyte, Skin pigmentation, Melanocortin receptors

A skin cell producing melanin. Target of melanocortin receptor agonist peptides. Important in dermatological research.
Related: Melanin, Skin cells, Pigmentation

G-protein coupled receptors responding to alpha-MSH and synthetic melanocortin agonists. MT-1, MT-2, and PT-141 target these receptors. Important in appetite and sexual function research.
Related: G-protein coupled receptors, Signal transduction, Appetite

A synthetic melanocortin receptor agonist. Melanotan-1 (MT-1) and Melanotan-2 (MT-2) are extensively researched. Studied for pigmentation and sexual function effects.
Related: Melanocortin receptors, Pigmentation, Sexual function

The sum of biochemical processes converting nutrients to energy and building blocks. Metabolic peptides (GLP-1 agonists, AICAR, MOTS-C) target these pathways.
Related: Energy production, Anabolism, Catabolism

A substance produced or consumed during metabolism. Peptide degradation products are metabolites. Important for understanding peptide breakdown.
Related: Metabolism, Degradation, Bioavailability

An IGF-1 splice variant upregulated by mechanical stress/exercise. Researched for satellite cell activation and muscle repair. Important in exercise-induced adaptation research.
Related: IGF-1, Muscle growth, Satellite cells

A concentration unit indicating peptide amount per unit volume. Standard for liquid peptide solutions and dosing calculations.
Related: Concentration, Dosing, Molarity

The simplified representation of a peptide’s atomic composition (e.g., C225H348N48O68 for tirzepatide). Listed on COAs. Essential for peptide identification.
Related: Molecular weight, Purity, CAS number

The mass of a peptide measured in g/mol (Daltons). Calculated from molecular formula. Listed on COAs and used for dosing calculations.
Related: Molecular formula, Concentration, Dosing

A mitochondrial-derived peptide activating AMPK and regulating energy homeostasis. Studied as an exercise mimetic and metabolic regulator. Emerging research area.
Related: Mitochondrial peptides, AMPK, Metabolic regulation

A negative regulator of muscle growth. Blocking myostatin with follistatin or ACE-031 promotes muscle hypertrophy. Central target in muscle biology research.
Related: Muscle growth, Follistatin, ActRIIB signalling

Peptides and proteins that block myostatin signalling to promote muscle growth. Include follistatin and ACE-031. Major research category.
Related: Myostatin, Muscle growth, Anabolic peptides

A coenzyme essential for energy metabolism, DNA repair, and sirtuin activation. Central to longevity and mitochondrial function research. Often supplemented alongside peptide research in anti-ageing protocols.
Related: Mitochondrial function, Longevity, Sirtuins

A class of endogenous opioid peptides produced by the body. Target of opioid research including studies on dermorphin and other peptide agonists.
Related: Opioid receptors, Analgesia, Endogenous peptides

A protein promoting nervous system cell growth and survival. Related to BDNF in neurotrophin family. Target in neuroprotection research.
Related: Neurotrophins, Neuroprotection, Neuroplasticity

The synapse connecting neurons to muscle fibres. Site of acetylcholine signalling. Target of botulinum toxin and neuromuscular research.
Related: Acetylcholine, Muscle contraction, Botulinum toxin

Peptides produced by and acting on the nervous system. Include semax, selank, epithalon, DSIP, and many others. Extensive research category.
Related: Neuromodulators, CNS, Signal transduction

The preservation of nervous system structure and function. Many peptides (semax, selank, colivelin) are studied for neuroprotective properties. Growing research field.
Related: Neurodegeneration, Neuropeptides, BDNF

A toxin damaging nervous system cells or function. Botulinum toxin is a neurotoxin studied in neuromuscular research.
Related: Botulinum toxin, Neurotoxicology, Mechanism of action

A chemical messenger in the nervous system (acetylcholine, dopamine, serotonin, etc.). Some peptides modulate neurotransmitter systems. Central to neuroscience research.
Related: Nervous system, Signal transduction, Brain function

A signalling molecule regulating vascular function and blood pressure. Arginine-containing peptides may enhance NO production. Important in cardiovascular research.
Related: Vasodilation, Cardiovascular function, Signalling

An enzyme metabolising NAD+ precursors. Target of 5-Amino-1MQ research, which inhibits NNMT to preserve NAD+ levels. Important in metabolic research.
Related: NAD+, Metabolism, Anti-ageing

A substance enhancing cognitive function (memory, focus, mental clarity). Semax, selank, and ADAMAX are researched as nootropic peptides.
Related: Cognitive enhancement, Neuropeptides, BDNF

A neuropeptide involved in appetite regulation and stress response. Some peptides modulate NPY signalling. Important in metabolic and behavioural research.
Related: Appetite regulation, Stress response, Neuromodulators

A neuropeptide promoting wakefulness and arousal. Orexin A and B are extensively researched. Important in sleep-wake regulation research.
Related: Sleep-wake cycle, Arousal, Hypothalamus

The concentration of osmotically active particles (osmoles) in a solution. Important in reconstitution — isotonic solutions prevent cell lysis or dehydration.
Related: Osmotic balance, Reconstitution, Cell biology

A 9-amino-acid neuropeptide involved in social bonding, stress reduction, and uterine contraction. Extensively researched in behavioural and reproductive research.
Related: Social behaviour, Stress response, Neurohormone

A tumour suppressor protein. Target of anticancer peptide research. PNC-27 is studied for p53-mediated apoptosis promotion.
Related: Tumour suppression, Cell apoptosis, Cancer research

A palmitoylated derivative of GHK-Cu with enhanced skin penetration. Studied for collagen synthesis and anti-ageing effects. Modification improves topical delivery.
Related: GHK-Cu, Collagen synthesis, Skin health

The addition of a palmitic acid chain to a peptide, increasing lipophilicity and cellular absorption. PAL-GHK and PAL-KTTKS are palmitoylated peptides. Important modification for enhancing delivery.
Related: Lipophilicity, Cellular uptake, Peptide modification

Cells in the pancreas producing insulin and glucagon. Target of GLP-1 agonist research. Important in glucose regulation research.
Related: Insulin, Glucagon, Glucose homeostasis

A short chain of amino acids (typically 2–50 amino acids; longer chains are proteins). Definition can vary, but most research peptides are < 100 amino acids. Central molecule of this field.
Related: Amino acid, Protein, Peptide bond

The covalent bond linking consecutive amino acids in a peptide. Formed between the carboxyl group of one amino acid and the amino group of the next. Can be cleaved by proteases.
Related: Amino acid linkage, Protein structure, Cleavage

A water-soluble polymer added to peptides to extend half-life by increasing molecular size and reducing renal clearance. PEG-MGF is a PEGylated mechano growth factor analogue.
Related: Half-life extension, Pharmacokinetics, Drug delivery

The covalent attachment of polyethylene glycol to a peptide. Extends pharmacokinetic half-life and improves solubility. Used in PEG-MGF and other long-acting peptide variants.
Related: Half-life, Drug delivery, Modification

The study of how the body absorbs, distributes, metabolises, and eliminates a peptide. Key parameters: half-life, absorption rate, bioavailability. Critical for understanding peptide dynamics.
Related: Half-life, Bioavailability, Clearance

The study of how a peptide produces biological effects. Mechanism of action, dose–response relationships, and efficacy are PD considerations. Complementary to pharmacokinetics.
Related: Mechanism of action, Efficacy, Dose–response

The observable characteristics of an organism or cell resulting from genotype + environment. Some peptides alter phenotype (e.g., melanocortin agonists increase melanin deposition). Important in studying peptide effects.
Related: Genotype, Gene expression, Observable traits

The addition of a phosphate group to a protein or peptide, typically activating signalling pathways. Many peptide mechanisms involve receptor phosphorylation triggering cascades.
Related: Signal transduction, Protein activation, Kinase

A major cell signalling cascade promoting survival and growth. Many growth factor-like peptides activate this pathway. Critical in cell biology research.
Related: Signal transduction, Cell survival, Growth factors

An endocrine gland producing melatonin, which regulates circadian rhythm. Source of pinealon and related bioregulator peptides. Important in sleep and anti-ageing research.
Related: Melatonin, Circadian rhythm, Endocrine system

An endocrine gland producing multiple hormones (growth hormone, prolactin, ACTH, FSH, LH). Target of many GH secretagogue peptides. Central to hormonal peptide research.
Related: Growth hormone, Hormones, Endocrine system

A family of protein kinases involved in cell signalling. Some peptides activate PKC pathways. Important in cell communication research.
Related: Kinases, Signal transduction, Protein activation

An anticancer peptide derived from p53-binding domain of HDM2. Designed to promote cancer cell apoptosis. Extensively researched in oncology.
Related: Anticancer peptides, p53, Apoptosis

Cells capable of differentiating into specialised cell types. Some peptides enhance progenitor cell differentiation and proliferation. Important in regenerative medicine research.
Related: Stem cells, Cell differentiation, Regeneration

A peptide hormone regulating lactation and other reproductive functions. Target of pituitary-modulating peptide research.
Related: Pituitary, Reproductive hormones, Lactation

An enzyme catalysing protein phosphorylation. Many peptide signalling pathways involve kinase activation. Central to cell signalling research.
Related: Phosphorylation, Signal transduction, Kinases

The ribosomal process of building proteins from amino acids directed by mRNA. IGF-1, HGH, and anabolic peptides promote protein synthesis. Critical in muscle growth research.
Related: Translation, Gene expression, Muscle growth

A protein core with attached glycosaminoglycan chains, important in extracellular matrix structure. Some peptides modify proteoglycan composition. Important in tissue structure research.
Related: ECM, Glycosaminoglycans, Tissue structure

An enzyme cleaving peptide bonds. Proteases degrade peptides over time; understanding protease sensitivity is important for stability and mechanism studies.
Related: Cleavage, Degradation, Enzyme kinetics

The enzymatic breakdown of proteins and peptides by proteases. Affects peptide stability. Important consideration in storage and shelf life.
Related: Protease, Degradation, Enzyme activity

A melanocortin 1 and 4 receptor agonist researched for erectile dysfunction and female sexual arousal. Peptide structure similar to alpha-MSH. Extensively studied in sexual function research.
Related: Melanocortin receptors, Sexual function, Alpha-MSH

The percentage of the desired peptide in a sample, determined by HPLC. Listed on COAs (typically >95% or >98%). Higher purity = fewer contaminants and impurities.
Related: HPLC, Quality control, COA, Specification

The testing and documentation procedures ensuring peptide identity, purity, potency, and safety. Third-party testing is standard. Documented via COAs.
Related: COA, HPLC, Purity testing

A protein on cell surfaces or intracellular that binds signalling molecules (agonists) and activates intracellular cascades. Most peptide effects occur through receptor binding.
Related: Agonist, Signal transduction, G-protein coupled receptors

A molecule blocking receptor activation. Distinct from agonist. Some research involves receptor antagonist peptides.
Related: Agonist, Receptor, Signal transduction

The process of dissolving lyophilised peptide powder in a solvent (bacteriostatic water, acetic acid, or saline). Required step before use. Affects peptide stability and degradation rate.
Related: Lyophilised powder, Bacteriostatic water, Solubility

Chemical reactions involving electron transfer. Antioxidant peptides like glutathione modulate cellular redox balance. Important in cellular protection research.
Related: Antioxidant, Oxidative stress, Cellular protection

The process of a denatured (unfolded) protein refold into its native 3D structure. Relevant for peptides that unfold during denaturation processes.
Related: Protein folding, Denaturation, Structure

A GLP-1/GIP/Glucagon triple receptor agonist peptide. Newer generation metabolic peptide with three simultaneous targets. Actively researched for obesity and metabolic disease.
Related: GLP-1, GIP, Glucagon, Metabolic peptides

Highly reactive oxygen-containing molecules (free radicals) that can damage cells. Antioxidant peptides (SS-31, glutathione) reduce ROS. Important in oxidative stress research.
Related: Oxidative stress, Antioxidant, Cellular damage

Age-related loss of muscle mass and strength. Target of myostatin inhibitor research and anabolic peptide studies. Growing research area due to ageing populations.
Related: Muscle loss, Ageing, Anabolic peptides

Muscle progenitor cells that fuse to existing fibres to increase muscle mass. IGF-1, MGF, and other anabolic peptides activate satellite cells. Important in muscle growth research.
Related: Muscle growth, Progenitor cells, IGF-1

The process of cells releasing molecules (hormones, proteins, peptides) into extracellular space or bloodstream. GH secretagogue peptides promote GH secretion from pituitary.
Related: Hormone release, Endocrine function, Pituitary

A synthetic nootropic peptide (Met-Glu-His-Phe-Pro-Gly-Pro) with BDNF-upregulating and neuroprotective properties. Extensively researched in cognitive and neuroprotection studies. Derived from ACTH fragment.
Related: Nootropic, BDNF, Neuropeptides

A GLP-1 receptor agonist with 94% amino acid homology to native GLP-1. Extensively researched for glucose control and weight loss. One of the most studied peptides globally.
Related: GLP-1, Metabolic peptides, Glucose regulation

A synthetic anxiolytic/nootropic peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) with BDNF-upregulating effects. Researched for anxiety reduction and cognitive enhancement. Russian-origin peptide.
Related: Nootropic, Anxiolytic, BDNF, Neuropeptides

Cellular ageing — cessation of cell division while remaining metabolically active. Anti-ageing peptides (epithalon, NAD+) target senescence pathways. Central to longevity research.
Related: Cellular ageing, Longevity, Telomeres

A synthetic GHRH analogue (29 amino acids). Stimulates GH secretion. Extensively researched as alternative to HGH for growth hormone axis support.
Related: GHRH, Growth hormone, GH secretagogues

Blood plasma with clotting factors removed. Used in cell culture research with peptides. Source of growth factors and binding proteins.
Related: Blood, Plasma, Cell culture

The cascade of molecular events by which cell surface receptors transmit information into cells. Most peptide effects occur via signal transduction pathways.
Related: Receptor signalling, Second messengers, Gene expression

A family of NAD+-dependent deacetylases regulating longevity and stress resistance. NAD+ is a critical sirtuin cofactor. Central targets in anti-ageing research.
Related: NAD+, Longevity, Anti-ageing

A SNARE protein involved in acetylcholine release. Cleavage target of botulinum toxin. Important in neuromuscular junction research.
Related: SNARE proteins, Acetylcholine, Botulinum toxin

Proteins mediating vesicle fusion and neurotransmitter release. Botulinum toxin cleaves SNARE proteins (SNAP-25, VAMP, SYNTAXIN), blocking acetylcholine release.
Related: Botulinum toxin, Acetylcholine, Neuromuscular junction

The ability of a peptide to dissolve in a solvent (water, bacteriostatic water, saline, acetic acid). Peptide hydrophobicity and charge affect solubility. Critical for reconstitution.
Related: Reconstitution, Hydrophobic/Hydrophilic, pH

An inhibitory peptide regulating hormone secretion. Relevant in endocrine research involving GH and insulin regulation.
Related: Hormone regulation, Neuroendocrinology, Inhibitory peptides

A pituitary cell producing growth hormone. Target of GH secretagogue peptide research.
Related: Growth hormone, Pituitary, Endocrine cells

The International Nonproprietary Name (INN) for human growth hormone (hGH). The 191-amino-acid form is identical to naturally occurring HGH.
Related: Growth hormone, HGH, INN

The selectivity of a peptide for its target receptor or biological pathway. Higher specificity = fewer off-target effects. Important in understanding mechanism of action.
Related: Selectivity, Potency, Mechanism of action

A lipid signalling molecule involved in vascular permeability and immune cell migration. Some peptides modulate S1P pathways. Important in inflammatory research.
Related: Lipid signalling, Inflammation, Immune function

A mitochondrial-targeting peptide reducing oxidative stress and improving cardiac function. Studied for cardiovascular protection and ageing. Unique mitochondrial penetration.
Related: Mitochondrial function, Oxidative stress, Cardioprotection

A protein family involved in gene transcription following receptor activation. Target of JAK-STAT pathway research. Important in immune signalling.
Related: JAK-STAT pathway, Gene expression, Signal transduction

A pluripotent cell capable of self-renewal and differentiation. Some peptides enhance stem cell function. Important in regenerative medicine research.
Related: Progenitor cells, Regeneration, Cell differentiation

The process of eliminating all microorganisms. Bacteriostatic water is sterilised but not sterile-filtered for clinical use (it’s preservative-based). Important safety consideration.
Related: Sterile, Bacteriostatic, Contamination

A molecule acted upon by an enzyme. Proteases use peptide bonds as substrates. Understanding substrate specificity is important for degradation research.
Related: Enzyme kinetics, Protease, Cleavage

Amino acids containing sulphur (cysteine, methionine). Important in disulfide bond formation and oxidative stress research. Often noted in peptide composition.
Related: Cysteine, Methionine, Disulfide bonds

The connection between neurons where neurotransmitters are released. Target of many neuropeptide studies. Critical in neuroscience research.
Related: Neurotransmitter, Nerve ending, Neural communication

The ability of synaptic connections to strengthen or weaken over time. BDNF-upregulating peptides enhance synaptic plasticity. Important in learning and memory research.
Related: Neuroplasticity, BDNF, Learning and memory

The formation of new synaptic connections. BDNF and neuropeptides promote synaptogenesis. Important in developmental and regenerative neuroscience.
Related: Synaptic plasticity, Neural growth, BDNF

An immune cell type central to adaptive immunity. Thymic peptides (thymosin, selank) enhance T-cell function. Important in immunology research.
Related: Immune system, Adaptive immunity, Thymus

A 43-amino-acid peptide with actin-sequestering and tissue-healing properties. One of the most researched peptides for wound healing and angiogenesis. Also called Thymosin Beta-4.
Related: Actin, Tissue repair, Angiogenesis

A superfamily of growth factors regulating cell proliferation, differentiation, and immune function. Myostatin is a TGF-β family member. Central to growth and fibrosis research.
Related: Growth factors, Myostatin, Cell differentiation

The maintenance of body temperature. Some peptides (MT-1, MT-2) may influence thermoregulation. Minor consideration in most research.
Related: Body temperature, Metabolism, Hormonal regulation

A thymic peptide extract or isolated peptide with immune-modulating properties. Studied for immune enhancement and anti-ageing effects. Derived from thymus gland.
Related: Thymic peptides, Immune function, Anti-ageing

Peptides produced by the thymus gland regulating T-cell development and immune function. Include thymosin alpha 1, thymalin, and others. Extensive anti-ageing and immune research.
Related: Thymus, T-cells, Immune function

A family of peptides produced by thymus gland tissue. Thymosin alpha 1 and thymosin beta-4 (TB500) are most researched. Crucial in immune and tissue repair studies.
Related: Thymic peptides, Immune function, T-cells

A 28-amino-acid thymic peptide enhancing T-cell function and immune response. Extensively researched for immune modulation and anti-ageing. Derived from thymus.
Related: Thymic peptides, Immune enhancement, T-cells

An endocrine gland producing thymic peptides and hosting T-cell development. Involutes (shrinks) with age. Target of anti-ageing and immune research.
Related: Thymic peptides, T-cells, Immune system

A family of pattern recognition receptors on immune cells. Some peptides modulate TLR signalling to enhance innate immunity.
Related: Immune function, Innate immunity, Receptor signalling

A pro-inflammatory cytokine. Anti-inflammatory peptides reduce TNF-α. Important marker in inflammation research.
Related: Inflammation, Cytokines, Immune response

Reduced responsiveness to a repeated stimulus. Occurs with peptides during chronic exposure. Important consideration in long-term peptide research protocols.
Related: Desensitisation, Tolerance development, Pharmacology

The sum of all amino acids in a peptide. Used in purity calculations. Important compositional data.
Related: Amino acids, Composition, Quality control

A molecular assay technique used in peptide binding and pharmacology studies. Advanced analytical method for measuring peptide–receptor interactions.
Related: Analytical techniques, Receptor binding, Assay

The process of copying DNA into messenger RNA. Gene expression regulation by peptides often occurs at transcription level. Central to understanding peptide effects.
Related: Gene expression, mRNA, Translation

The introduction of foreign DNA/RNA into cells. Used to study peptide effects on gene expression. Important in molecular biology research.
Related: Genetic engineering, Gene expression, Cell biology

The ribosomal synthesis of protein from mRNA. Anabolic peptides enhance translation. Key step in protein synthesis research.
Related: Gene expression, Protein synthesis, Ribosomes

A membrane protein moving molecules across cell membranes. Some peptides modulate transporters. Important in cellular uptake research.
Related: Cell membrane, Active transport, Cellular uptake

An amino acid and precursor to serotonin. Appears in some peptide sequences. Important in neurotransmitter research.
Related: Amino acids, Serotonin, Mood regulation

A protein complex regulating mTOR signalling. Some growth factor peptides signal through mTOR, which TSC1/TSC2 inhibits. Important in cell growth regulation.
Related: mTOR pathway, Growth factors, Cell growth

The predominant collagen type in skin, bone, and connective tissue. Target of anti-ageing and tissue repair peptides. Most abundant human protein.
Related: Collagen, ECM, Skin health

A regulatory protein tagging other proteins for degradation via the proteasome. HDM2 (target of PNC-27) is an ubiquitin ligase. Important in protein quality control.
Related: Protein degradation, Proteasome, Regulation

The covalent attachment of ubiquitin to a protein, typically marking it for degradation. Important in cellular regulation and cancer biology.
Related: Ubiquitin, Protein degradation, Cell regulation

A nitrogen-containing compound. Used in some peptide storage buffers. Marks degradation if found in excess on COAs.
Related: Nitrogen metabolism, Peptide storage, Contaminants

A growth factor promoting angiogenesis. Target of pro-angiogenic peptide research (BPC-157, TB500, GHK-Cu). Central to tissue repair and regeneration.
Related: Angiogenesis, Growth factors, Tissue repair

Narrowing of blood vessels. Opposite of vasodilation. Some peptides affect vascular tone.
Related: Cardiovascular function, Blood pressure, Vasodilation

Widening of blood vessels increasing blood flow. VIP and nitric oxide-promoting peptides cause vasodilation. Important in cardiovascular research.
Related: Blood flow, Blood pressure, Cardiovascular function

A 28-amino-acid neuropeptide regulating gut motility, immune function, and vascular tone. Extensively researched in neurobiology and immunology.
Related: Neuropeptides, Gut function, Immune modulation

A peptide hormone regulating water reabsorption and blood pressure. Related to oxytocin structurally. Important in neuroendocrine research.
Related: Peptide hormones, Water balance, Blood pressure

A SNARE protein involved in acetylcholine release. Cleaved by botulinum toxin. Target in neuromuscular research.
Related: SNARE proteins, Botulinum toxin, Acetylcholine release

The percentage of living cells in a culture. Peptides are tested for cell toxicity by measuring viability reduction. Important in safety research.
Related: Cell culture, Toxicity testing, Cell health

A virus engineered to deliver genes into cells. Used in some peptide gene therapy research. Important in genetic medicine.
Related: Gene therapy, Genetic engineering, Cell transduction

The pathological loss of muscle mass. Myostatin inhibitors and anabolic peptides target muscle wasting in sarcopenia and disease contexts.
Related: Sarcopenia, Muscle loss, Anabolic peptides

Dissolving readily in water. Hydrophilic peptides are water-soluble. Important for reconstitution considerations.
Related: Hydrophilic, Solubility, Reconstitution

The complex process of repairing tissue damage. BPC-157, TB500, GHK-Cu, and other peptides are extensively researched for promoting wound healing. Major research application.
Related: Tissue repair, Angiogenesis, Inflammation

A key developmental and regenerative pathway. Some peptides modulate Wnt signalling. Important in stem cell and regeneration research.
Related: Signal transduction, Stem cell biology, Regeneration

An analytical technique determining 3D protein/peptide structures. Used to study peptide–receptor interactions. Advanced structural biology tool.
Related: Structural analysis, Protein structure, Analytical techniques

A molecular biology technique studying protein–protein interactions. Used in peptide–receptor binding research. Important in understanding mechanism of action.
Related: Protein interaction, Molecular biology, Mechanism studies

A measure of peptide charge in solution, affecting aggregation and stability. Important in formulation research and quality control.
Related: Peptide charge, Stability, Formulation

DNA-binding domains with zinc coordination. Some regulatory peptides contain zinc-finger-like structures. Important in gene regulation research.
Related: Protein structure, Gene regulation, Transcription factors