Research Peptide Glossary A–Z | QSC — 46 Terms Defined
QSC · RESEARCH CATALOG
Research Peptide Glossary — A to Z 46 Terms Defined · HPLC · COA · Receptors · Mechanisms · Compounds · Techniques
Complete glossary of research peptide terminology. From AMPK to VEGFR2 — every term you encounter in peptide research defined clearly and in context. Covers analytical chemistry, receptor biology, compound-specific mechanisms, and QSC-specific verification terms.
Adrenocorticotropic hormone. Pituitary peptide stimulating cortisol production from adrenal cortex. Elevated by GHRP-2, GHRP-6, Hexarelin (GHS-R1a agonists) — not by Ipamorelin (selective GHS-R1a agonist).
AMY1R
Amylin receptor 1. Target of Cagrilintide (long-acting amylin agonist). Mediates satiety via hindbrain/brainstem pathway — distinct from GLP-1R hypothalamic pathway. Dual activation (CagriSema) shows additive weight loss.
AMPK
AMP-activated protein kinase. Master energy sensor activated by MOTS-c (mitochondria-derived peptide) and exercise. Regulates glucose uptake, fatty acid oxidation, mitochondrial biogenesis. Key longevity signaling node.
B
Bacteriostatic Water
Sterile water with 0.9% benzyl alcohol preservative. Standard diluent for research peptide reconstitution — benzyl alcohol inhibits bacterial growth for multi-use vials. Distinct from sterile water (no preservative, single-use only).
Bioavailability
Fraction of compound reaching systemic circulation. Most research peptides have poor oral bioavailability (GI protease degradation). Exception: some Khavinson dipeptides (Glu-Trp, Lys-Glu) show reported oral activity. Research use only.
Bioregulator
Khavinson Institute term for short (2-5 AA) tissue-specific peptides acting epigenetically to restore youthful gene expression in target organs. Examples: Epitalon (pineal), Thymagen (thymus), Pancragen (pancreas), Cortagen (brain).
BPC-157
Body Protection Compound 157. Stable 15-AA gastric pentadecapeptide. Acts via NOS/VEGFR2/EGF/FAK-paxillin pathways. Studies: tendon healing, GI mucosal repair, angiogenesis, neuroprotection. Unique stability in gastric acid. Research use only.
C
Cardiolipin
Signature phospholipid of the inner mitochondrial membrane (IMM). Target of SS-31 (Elamipretide). Cardiolipin integrity maintains cristae structure, Complex I/II function, and prevents cytochrome c release.
COA
Certificate of Analysis. Document confirming peptide compound identity (mass spectrometry) and purity (HPLC chromatogram). Independent COA (Janoshik): published by third-party lab at verify.janoshik.com. In-house COA: supplier-generated, unverifiable.
CJC-1295
Modified GHRH 1-29 with DAC (Drug Affinity Complex) albumin-binding modification. Half-life: 6-8 days vs 7 min native GHRH. Sustained GHRH-R pituitary stimulation. Distinct from CJC-1295 without DAC (MOD GRF 1-29, 30-min half-life).
D
DAC
Drug Affinity Complex. Albumin-binding maleimide modification on CJC-1295. Binds serum albumin non-covalently → protected from plasma proteases → 6-8 day half-life. Responsible for ‘long-acting’ CJC-1295 property.
G
GCGR
Glucagon receptor. Third target of Retatrutide (triple agonist, GLP-1R/GIPR/GCGR). GCGR activation increases hepatic fat mobilization, brown adipose thermogenesis, and energy expenditure — mechanism for Retatrutide’s superior weight loss vs dual agonists.
GHK-Cu
Glycine-Histidine-Lysine Copper tripeptide. Naturally occurring in plasma. Acts on ECM remodeling: collagen synthesis upregulation, MMP rebalancing, VEGF/FGF stimulation. Studies: wound healing, anti-fibrotic, hair follicle, skin aging. Research use only.
GHS-R1a
Growth hormone secretagogue receptor 1a (ghrelin receptor). Target of Ipamorelin, GHRP-2, GHRP-6, Hexarelin, MK-677. GHS-R1a agonism releases GH from pituitary somatotrophs. Independent of GHRH-R — additive GH release when combined with GHRH analogues.
GHRH-R
Growth hormone releasing hormone receptor. Target of Sermorelin, CJC-1295, Tesamorelin, MOD GRF 1-29. GHRH-R agonism stimulates GH from anterior pituitary. Independent of GHS-R1a — synergistic with GHS-R1a agonists.
Glucose-dependent insulinotropic polypeptide receptor. Second target of Tirzepatide (dual) and Retatrutide (triple). GIPR adds adipose tissue insulin sensitivity and enhanced incretin effect to GLP-1R signaling.
H
hTERT
Human telomerase reverse transcriptase. Catalytic subunit of telomerase enzyme — extends telomeres by adding TTAGGG repeats. Activated by Epitalon (Ala-Glu-Asp-Gly tetrapeptide, Khavinson Institute). hTERT activation is primary anti-aging mechanism of Epitalon.
HPLC
High-Performance Liquid Chromatography. Gold standard for research peptide purity measurement. Separates peptide components by differential column retention — outputs chromatogram showing peaks. Purity = target peak area ÷ total area × 100%. Research grade: ≥99% HPLC.
I
Ipamorelin
Selective GHS-R1a agonist hexapeptide. Most selective GH secretagogue: zero cortisol, zero prolactin, zero ACTH elevation. Combined with CJC-1295 (GHRH-R) for additive GH release via independent pathways. Research use only.
J
Janoshik
Independent Czech analytical laboratory. Processes 150-200 peptide/hormone samples daily using Shimadzu HPLC and LC-MS. Publishes results at verify.janoshik.com post-test. QSC submits every batch. Researchers verify independently by batch code — no supplier trust required.
K
Khavinson
Prof. Vladimir Khavinson, Director, St. Petersburg Institute of Bioregulation and Gerontology. Author of 40+ years of peptide bioregulator research. Developed Epitalon, Thymalin, Thymagen, Pancragen, Cortagen, and 20+ other tissue-specific short peptides studied for longevity.
KISS1R
Kisspeptin receptor (GPR54). Target of Kisspeptin-10 (C-terminal decapeptide of KISS1 gene product). KISS1R activation at hypothalamic GnRH neurons → pulsatile GnRH release → LH/FSH → testosterone/estrogen. Master HPG axis regulator.
L
Lyophilization
Freeze-drying process: peptide dissolved in aqueous solution → frozen → water removed by sublimation under vacuum. Produces white/off-white powder with extended stability (2-3 years at −20°C). Standard final form for all QSC research peptides.
M
MC4R
Melanocortin-4 receptor. Target of PT-141 (Bremelanotide) and Semax (ACTH 4-10 analogue). MC4R activation in hypothalamus → dopamine pathway → desire/arousal signaling (PT-141) or BDNF/NGF upregulation (Semax). Central mechanism — distinct from peripheral PDE5 pathway.
MOTS-c
Mitochondrial Open Reading Frame of 12S rRNA type-c. 16-AA peptide encoded in mitochondrial DNA. Activates AMPK → glucose uptake ↑, lipogenesis ↓, FAO ↑, insulin sensitivity ↑. Exercise-responsive — levels increase with aerobic activity. Declines with age. Research use only.
MS
Mass Spectrometry. Analytical technique confirming compound identity by molecular weight measurement. Complementary to HPLC: HPLC = purity; MS = identity. QSC COAs include both HPLC chromatogram and MS molecular weight confirmation.
N
Net Peptide Content (NPC)
Fraction of vial weight that is actual peptide vs residual moisture and salt counterions (TFA/acetate). A peptide can be 99% HPLC pure but 70% NPC — 30% is water and salt. NPC matters for dosing calculations.
NAD+
Nicotinamide Adenine Dinucleotide. Substrate for SIRT1-7 sirtuins (epigenetic regulation) and PARP1/2 (DNA repair). Mitochondrial Complex I cofactor. Declines ~50% between ages 40-60. QSC stocks at ≥99% HPLC with Janoshik COA.
Poly ADP-ribose polymerase. DNA strand break repair enzyme requiring NAD+ as substrate. PARP1/2 activity depletes NAD+ during DNA damage — one mechanism of age-related NAD+ decline. NAD+ supplementation restores PARP repair capacity.
Peptide Bond
Chemical bond (-CO-NH-) linking amino acids in a polypeptide chain. Formed by condensation between α-carboxyl of one amino acid and α-amino group of the next. Can be hydrolyzed by proteases — reason most peptides cannot be taken orally.
PT-141
PT-141 (Bremelanotide). Cyclic lactam analogue of alpha-MSH (melanocyte-stimulating hormone). MC4R/MC3R agonist. FDA-approved as Vyleesi (Palatin/AMAG, 2019) for HSDD in premenopausal women. Central arousal mechanism distinct from PDE5 inhibitors. Research use only.
R
Retatrutide
LY3437943. Triple GLP-1R/GIPR/GCGR agonist (Eli Lilly). Phase 2: −24.2% weight loss at 36 weeks (12mg). Phase 3 ongoing. GCGR addition (vs Tirzepatide dual) increases energy expenditure via BAT and hepatic fat mobilization. QSC stocks at ≥99% HPLC.
S
Semaglutide
GLP-1R monoagonist. FDA-approved as Ozempic (T2DM) and Wegovy (obesity). Phase 3 STEP 1: −14.9% at 68 weeks. Acylated for albumin binding → 7-day half-life. QSC stocks research-grade semaglutide at ≥99% HPLC with Janoshik COA. Research use only.
Sermorelin
Synthetic GHRH 1-29 (first 29 amino acids of native GHRH). Short half-life (~10-20 min) preserves pulsatility. FDA-approved history (Geref, Serono). Combined with Ipamorelin for physiological dual-pathway GH research. Research use only.
Solid-Phase Peptide Synthesis. Standard method for research peptide production. Amino acids assembled one at a time on solid resin using Fmoc or Boc protecting group chemistry. After synthesis: cleavage → HPLC purification → lyophilization → sealed vial.
SS-31
Szeto-Schiller Peptide 31 (Elamipretide, D-Arg-Dmt-Lys-Phe-NH2). Mitochondria-targeted tetrapeptide. Concentrates 1000× in inner mitochondrial membrane via cardiolipin binding. Phase 2 data: heart failure (HOPEFUL-1), Barth syndrome, mitochondrial myopathy. Research use only.
T
TB-500
Thymosin Beta-4 fragment (Tβ4). 43-AA actin-sequestering peptide. Sequesters G-actin via LKKTET domain → cellular migration. Anti-inflammatory via NF-κB. Systemic reach: cardiac, neural, musculoskeletal stem cell homing. Distinct from Thymosin Alpha-1 (immune modulator).
Tesamorelin
GHRH 1-44 analogue with trans-3-hexenoic acid stability modification. FDA-approved as Egrifta (Theratechnologies) for HIV-associated abdominal lipodystrophy. Full-length GHRH 1-44 structure vs CJC-1295’s truncated 1-29. QSC stocks at ≥99% HPLC. Research use only.
Thymalin
Thymic polypeptide extract (Khavinson bioregulator). T-cell differentiation restoration, thymic involution reversal in aged models. Combined with Epitalon in Khavinson’s own protocol showing 24-42% lifespan extension. Research use only.
Thymosin Alpha-1
Tα1, Thymalfasin (Zadaxin). 28-AA thymic peptide. TLR9 agonism → dendritic cell maturation → NK cell enhancement → Th1 cytokines (IL-2, IFN-γ). Approved in 35+ countries for hepatitis B/C. Distinct from Thymosin Beta-4 (different family, different mechanism).
Tirzepatide
Dual GLP-1R/GIPR agonist (Eli Lilly). FDA-approved as Mounjaro (T2DM) and Zepbound (obesity). Phase 3 SURMOUNT-1: −22.5% at 72 weeks (15mg). GIPR adds adipose insulin sensitivity to GLP-1R. QSC stocks research-grade at ≥99% HPLC. Research use only.
TLR9
Toll-Like Receptor 9. Pattern recognition receptor for bacterial/viral DNA. Target of Thymosin Alpha-1 (Tα1). TLR9 activation → type I interferon → innate immune activation → dendritic cell maturation. Key antiviral mechanism of Tα1.
V
VEGFR2
Vascular endothelial growth factor receptor 2. Upregulated by BPC-157. VEGFR2 activation → angiogenesis, new capillary formation, vascular repair. Key mechanism in BPC-157’s healing effects on tendons, ligaments, and ischemic tissue.
verify.janoshik.com
Janoshik’s public COA verification platform. Any researcher can enter a QSC batch code to retrieve the independent test result directly from Janoshik’s database — showing HPLC purity, MS identity, compound name, and test date. Requires zero trust in QSC.
QSC Research Catalog
80+ Compounds · ≥99% HPLC · Janoshik COA · verify.janoshik.com
