Peptide Research Glossary

A cellular energy sensor activated when ATP is low. Triggers fatty acid oxidation, glucose uptake, and mitochondrial biogenesis. AICAR and MOTS-c activate AMPK pathways, mimicking exercise-like metabolic effects.

A hormone co-secreted with insulin from pancreatic beta cells. Suppresses glucagon, slows gastric emptying, and promotes satiety. Amylin analogs like cagrilintide mimic this action for weight management.

The physiological process by which new blood vessels grow from pre-existing vessels. Driven by VEGF, FGF, and HIF-1α signaling. BPC-157 and TB-500 both promote angiogenesis through distinct mechanisms - key to their tissue healing effects.

Programmed cell death - a tightly regulated process cells use to self-destruct. Distinct from necrosis. Dysregulated apoptosis underlies cancer (too little) and neurodegeneration (too much). Several peptides modulate apoptotic pathways to exert cytoprotective or anti-tumor effects.

A cellular housekeeping process that degrades and recycles damaged proteins and organelles via lysosomes. Activated by fasting, caloric restriction, and mTOR inhibition. Linked to longevity and cancer suppression. Rapamycin and some peptides upregulate autophagic flux.

The addition of an acetyl group to a protein. Histone acetylation loosens chromatin and activates gene expression. Sirtuin enzymes (which require NAD+) are deacetylases that reverse this modification, linking NAD+ metabolism to epigenetic regulation.

Sterile water preserved with 0.9% benzyl alcohol to inhibit bacterial growth. The standard diluent for reconstituting research peptides. Allows a vial to remain in use for up to 28 days. See: Bacteriostatic Water Guide →

A protein that supports neuronal survival, growth, and synaptic plasticity. Peptides like Semax and P21 upregulate BDNF expression, contributing to their nootropic effects. Low BDNF is associated with depression and cognitive decline.

The fraction of a drug that reaches systemic circulation unchanged. Subcutaneous peptide injection typically yields 70–90% bioavailability. Oral peptide bioavailability is often near zero due to GI proteolysis - unless specifically engineered for oral use (e.g., Semaglutide tablets).

A 15-amino-acid synthetic peptide derived from a gastric protein. Widely researched for tissue healing, gut repair, and anti-inflammatory effects. Stable in gastric acid, allowing oral bioavailability. See: BPC-157 Wiki → | Calculator →

A universal intracellular second messenger that relays signals from cell surface receptors (GPCRs) to downstream effectors. Activates protein kinase A (PKA), which regulates metabolic enzymes, ion channels, and gene transcription.

A modified GHRH analog. No DAC form: short-acting (~30 min). With DAC: long-acting (~8 day half-life). See: CJC-1295 Wiki → | Calculator →

The most abundant protein in the body, forming the structural scaffold of tendons, ligaments, skin, and bone. Type I collagen is the primary structural form. BPC-157, GHK-Cu, and TB-500 all promote collagen synthesis through distinct signaling pathways.

The amount of dissolved peptide per unit volume of solution. Calculated as: Vial Strength ÷ Reconstitution Volume. The foundation of every ASCEND draw calculation.

Small signaling proteins secreted by immune and other cells to regulate inflammation, immune response, and cell communication. Pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) drive tissue damage; anti-inflammatory cytokines (IL-10, IL-4) resolve it. Many peptides modulate cytokine balance.

A reactive maleimide group added to CJC-1295 that covalently binds to circulating albumin. Extends half-life from ~30 minutes to ~8 days, enabling once-weekly dosing.

A catecholamine neurotransmitter central to reward, motivation, motor control, and neuroendocrine regulation. Dopaminergic system dysfunction underlies Parkinson's disease, ADHD, and addiction. Selank and BPC-157 both interact with dopaminergic pathways.

The quantitative relationship between the dose of a compound and the magnitude of its effect. A key criterion for establishing biological activity. Peptide studies that lack a clear dose-response curve are considered weak evidence of efficacy.

The graduation line to draw to on a 100-unit insulin syringe. Calculated as: Liquid Volume (mL) × 100. Example: 0.167 mL = draw to the 16.7 (roughly 17) line.

Endogenous opioid pentapeptides (Met-enkephalin and Leu-enkephalin) that bind μ- and δ-opioid receptors to modulate pain and mood. Selank's anxiolytic effect is partly attributed to inhibition of enkephalinase, the enzyme that degrades enkephalins.

An enzyme in vascular endothelial cells that produces nitric oxide (NO) from L-arginine. NO causes smooth muscle relaxation and vasodilation. BPC-157 upregulates eNOS - the primary mechanism behind its pro-angiogenic and cytoprotective vascular effects.

A dosing frequency of once every 48 hours. Common for peptides with intermediate half-lives (BPC-157, TB-500). The ASCEND Protocol Tracker automatically calculates EOD schedules from a start date.

A synthetic tetrapeptide (Ala-Glu-Asp-Gly) from the pineal gland bioregulator epithalamin. Studied for telomerase activation and longevity. See: Epithalon Wiki →

The primary cell type of connective tissue. Fibroblasts synthesize collagen, elastin, and other extracellular matrix components critical for structural support and wound repair. BPC-157 and TB-500 both stimulate fibroblast migration and proliferation to accelerate tissue healing.

A metabolic pathway that generates one-carbon units for nucleotide synthesis, methylation reactions, and amino acid homeostasis. MOTS-c inhibits the enzyme MTHFD1 in this cycle, causing AICAR accumulation and downstream AMPK activation.

The principal inhibitory neurotransmitter of the central nervous system. Acts on GABA-A (ionotropic) and GABA-B (metabotropic) receptors to reduce neuronal excitability. Selank produces anxiolytic effects partly through GABA-A receptor modulation, similar to benzodiazepines but without sedation or dependence.

A naturally occurring copper complex (Gly-His-Lys-Cu²⁺) found in human plasma. Stimulates collagen and elastin synthesis, promotes wound healing. See: GHK-Cu Wiki →

A hypothalamic neuropeptide that stimulates the pituitary to release growth hormone. Sermorelin, CJC-1295, and Tesamorelin are synthetic GHRH analogs.

An endogenous peptide hormone produced by the stomach. Acts on the GHS-R1a receptor to stimulate GH release and increase appetite. GHRPs like GHRP-6 and Hexarelin mimic ghrelin's GH-releasing action. GHRP-6 strongly activates ghrelin-mediated appetite signaling; Ipamorelin does not.

GLP-1 (Glucagon-Like Peptide-1) and GIP (Glucose-dependent Insulinotropic Polypeptide) are incretin hormones released after meals to stimulate insulin secretion and suppress glucagon. Target receptors for Semaglutide (GLP-1), Tirzepatide (dual GLP-1/GIP), and Retatrutide (triple GLP-1/GIP/glucagon).

The time required for the plasma concentration of a substance to fall to half its initial value. Determines dosing frequency. Short: BPC-157 (4–6 hrs), Ipamorelin (2 hrs). Long: Semaglutide (7 days), CJC-1295 w/DAC (~8 days).

The tendency of biological systems to maintain stable internal conditions despite external changes. Most peptide hormones act as homeostatic regulators - correcting deviations from setpoints for glucose, growth hormone, cortisol, and other physiological variables.

The central stress response system. The hypothalamus releases CRH → pituitary releases ACTH → adrenal glands release cortisol. Selank and other anxiolytic peptides modulate HPA axis reactivity, blunting cortisol response to stressors.

An analytical technique that separates, identifies, and quantifies mixture components. Used in batch testing to verify peptide purity (% by area). ASCEND's verification standard requires HPLC analysis from independent labs. See: Verification →

A peptide hormone produced primarily in the liver in response to growth hormone. Mediates most anabolic GH effects including muscle protein synthesis, cellular growth, and satellite cell activation. See: IGF-1 Wiki → | Calculator →

A protective biological response to tissue damage or infection, characterized by redness, heat, swelling, and pain. Acute inflammation is beneficial; chronic inflammation underlies most modern diseases. Many peptides (BPC-157, KPV, GHK-Cu) exert anti-inflammatory effects via NF-κB suppression and cytokine modulation.

Injection directly into muscle tissue. Faster onset than subcutaneous for most compounds. Used for some long-acting depot formulations (e.g., Triptorelin microspheres). Less common than subcutaneous for research peptide protocols.

Delivery of a compound via the nasal mucosa. Provides rapid CNS access by bypassing the blood-brain barrier through the olfactory pathway. Used for nootropic and anxiolytic peptides: Semax, Selank, and DSIP are commonly administered intranasally.

Studies conducted in a controlled laboratory environment outside a living organism (e.g., in cell cultures or test tubes). In vitro results are preliminary - effects may not translate to living animals or humans.

Studies conducted in a living organism (animal or human). Considered stronger evidence than in vitro. Most peptide research is in vivo rodent studies; human clinical trials represent the highest evidence tier.

On an insulin syringe: graduation markings where 100 IU = 1 mL. ASCEND displays draw values in IU for direct syringe reading.

The predominant cell type of the epidermis (outer skin layer), constituting ~90% of skin cells. Critical to wound re-epithelialization. TB-500 and GHK-Cu promote keratinocyte migration during wound closure.

The standard storage form for most research peptides. Water is removed by freezing then sublimation under vacuum, yielding stable dry powder with extended shelf life. Requires reconstitution with BAC water before use.

Measures the mass-to-charge ratio of ions to confirm molecular identity. Used with HPLC to verify that a peptide sample is the correct compound. See: Verification →

A family of G protein-coupled receptors (MC1R–MC5R) that bind POMC-derived peptides including α-MSH, ACTH, and β-endorphin. MC1R governs skin pigmentation; MC3R and MC4R regulate energy homeostasis and sexual function. PT-141 and Melanotan II are melanocortin receptor agonists.

Organelles that generate ATP through oxidative phosphorylation. Central to cellular energy production, apoptosis, and reactive oxygen species (ROS) management. Mitochondrial dysfunction is implicated in aging and metabolic disease. MOTS-c and Humanin are mitochondria-derived peptides (MDPs) with systemic signaling roles.

A 16-amino acid peptide encoded in the mitochondrial 12S rRNA gene. Activates AMPK, improves insulin sensitivity, and enhances exercise capacity. See: MOTS-c Wiki →

A central kinase that integrates nutrient, energy, and growth factor signals to regulate protein synthesis, cell growth, autophagy, and lifespan. mTORC1 activation promotes anabolism; inhibition (by rapamycin, caloric restriction) promotes autophagy and longevity. IGF-1 and insulin strongly activate mTOR.

A master transcription factor that controls expression of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), adhesion molecules, and survival genes. Chronic NF-κB activation drives inflammatory disease. KPV, GHK-Cu, and BPC-157 all suppress NF-κB signaling as part of their anti-inflammatory mechanisms.

The formation of new blood vessels in tissue, including both angiogenesis (sprouting from existing vessels) and vasculogenesis (de novo formation). Critical for supplying oxygen and nutrients to healing tissue. BPC-157, TB-500, and VEGF are key mediators.

The process of generating new neurons. In adults, occurs primarily in the hippocampal dentate gyrus and olfactory bulb. BDNF, NGF, and VEGF promote adult neurogenesis. Semax and Dihexa enhance neurogenic signaling, supporting their nootropic and neuroprotective profiles.

The preservation of neuronal structure and function against damage from ischemia, excitotoxicity, oxidative stress, or neurodegeneration. Neuroprotective peptides include Semax (BDNF upregulation), BPC-157 (dopaminergic protection), and Selank (anti-excitotoxic GABA modulation).

A gaseous signaling molecule produced by nitric oxide synthase (NOS) enzymes. In blood vessels, eNOS-derived NO causes smooth muscle relaxation and vasodilation. At high concentrations (iNOS), NO is cytotoxic and antimicrobial. BPC-157's vascular effects are primarily mediated through NO pathway modulation.

A compound that enhances cognitive function - memory, focus, processing speed, or neuroprotection - without significant side effects. Peptide nootropics include Semax (BDNF upregulation), Selank (anxiolytic + memory), Dihexa (HGF/MET agonism), and P21 (CNTF analog).

An imbalance between reactive oxygen species (ROS) production and antioxidant defenses, leading to cellular damage. A core mechanism of aging and chronic disease. GHK-Cu activates the NRF2/ARE antioxidant pathway; NAD+ supports SIRT3-mediated mitochondrial ROS management.

A short chain of amino acids (typically 2–50) linked by peptide bonds. Peptides act as signaling molecules, hormones, and growth factors. Research peptides are synthetic versions of endogenous sequences or novel engineered analogs.

The study of how a drug moves through the body: absorption, distribution, metabolism, and excretion (ADME). PK parameters like Cmax, Tmax, and half-life inform dosing frequency and route selection.

The "master gland" at the base of the brain. The anterior pituitary releases GH, LH, FSH, TSH, ACTH, and prolactin in response to hypothalamic releasing hormones. GHRPs and GHRHs act on the anterior pituitary to stimulate GH secretion. The posterior pituitary releases oxytocin and vasopressin.

A clinical study design in which some participants receive an inactive treatment (placebo) to isolate the true drug effect. The gold standard of clinical evidence. Most peptide data lacks placebo-controlled human trials - the critical evidence gap compared to FDA-approved drugs.

A large precursor protein produced in the anterior pituitary and hypothalamus. Cleaved into multiple active peptides including ACTH, α-MSH, β-endorphin, and γ-MSH - all of which act on melanocortin receptors or opioid receptors to regulate stress response, pigmentation, and energy balance.

A protein structure that binds a specific signaling molecule (ligand) and initiates a biological response. Agonists activate receptors; antagonists block them. Peptides exert their effects by binding to specific receptors - GPCRs, RTKs, nuclear receptors, or ion channels.

Dissolving a lyophilized peptide with a diluent (typically BAC water) to create an injectable solution. Volume used determines concentration. See: Reconstitution Guide →

How a substance enters the body. Common peptide routes: subcutaneous injection (SQ), intramuscular injection (IM), and intranasal spray. Route affects onset, bioavailability, and duration of action.

A compound that causes secretion of another substance. Growth hormone secretagogues (GHS) stimulate the pituitary to release GH. Examples: Ipamorelin, GHRP-2, GHRP-6, Hexarelin, MK-677.

A state of permanent cell cycle arrest in which damaged cells remain metabolically active and secrete inflammatory signals (the Senescence-Associated Secretory Phenotype, SASP). Senescent cells accumulate with age and drive chronic inflammation. Senolytics selectively eliminate them.

A compound that selectively kills senescent cells. FOXO4-DRI is a peptide senolytic studied in aging research. Clearing senescent cells reduces the SASP-driven inflammation that accelerates tissue aging.

A monoamine neurotransmitter that regulates mood, appetite, sleep, and cognition. ~90% is produced in the gut by enterochromaffin cells; ~10% in the brain. Selank and BPC-157 both modulate serotonergic signaling, contributing to their mood-stabilizing effects.

A family of NAD+-dependent deacylase enzymes that regulate gene expression, DNA repair, and metabolic adaptation. SIRT1 deacetylates PGC-1α to promote mitochondrial biogenesis; SIRT3 maintains mitochondrial function. Declining NAD+ with age limits sirtuin activity - the core rationale for NAD+ supplementation.

Injection into the tissue layer between skin and muscle. The most common route for research peptide administration. Uses a 28–31 gauge needle, 5/16–½ inch. ASCEND draw calculations are calibrated for 100-unit subcutaneous insulin syringes.

A synthetic fragment of Thymosin Beta-4 (Tβ4), an actin-regulating protein involved in cell migration, angiogenesis, and tissue repair. See: TB-500 Wiki → | Calculator →

Protective caps of repetitive DNA (TTAGGG repeats) at chromosome ends, analogous to shoelace aglets. Shorten with each cell division; critically short telomeres trigger senescence or apoptosis. Telomere length is a biomarker of biological aging. Epithalon is studied for its ability to activate telomerase.

An enzyme (ribonucleoprotein) that adds TTAGGG repeats to chromosome ends, counteracting telomere shortening. Active in stem cells and germ cells; largely repressed in somatic cells. Reactivating telomerase is a proposed anti-aging strategy. Epithalon is reported to upregulate telomerase expression in vitro.

A dual GIP and GLP-1 receptor agonist. FDA-approved as Mounjaro (T2DM) and Zepbound (obesity). See: Tirzepatide Wiki → | Calculator →

Widening of blood vessels through relaxation of smooth muscle in vessel walls, increasing blood flow and reducing vascular resistance. Primarily mediated by nitric oxide (NO), prostacyclin, and neuropeptides. BPC-157 promotes vasodilation via eNOS upregulation and NO production.

The primary driver of angiogenesis. Binds VEGFR receptors on endothelial cells to stimulate vessel sprouting, migration, and proliferation. Upregulated by hypoxia (via HIF-1α), BPC-157, and TB-500. Cancer therapies (bevacizumab) block VEGF to starve tumors of blood supply.

The total mass of peptide in a vial, expressed in mg (or IU for HCG). One of the two inputs to the ASCEND concentration formula. Common sizes: 1 mg (IGF-1 LR3), 2 mg (BPC-157), 5000 IU (HCG).