Research notes
How we test, how to read a certificate, and how to handle what you order. Research context only.
How independent purity testing works, from sample to certificate
What an independent lab measures, and why HPLC and mass spectrometry together give a purity figure you can trust.
PepNex Research · May 2026Reading an HPLC chromatogram: peaks, retention time, and purity
Peaks, retention time, and how the dominant peak relates to the purity figure on a certificate.
PepNex Research · Apr 2026Cold-chain handling and storage for lyophilised research peptides
How to store lyophilised research peptides, and what changes once a vial is reconstituted.
PepNex Research · Apr 2026PT-141: the melanocortin agonist melanotan II left behind
A cyclic heptapeptide and metabolite of melanotan II, used as a research tool to probe melanocortin-receptor signalling at MC1R, MC3R and MC4R. Research use only.
Elena Sorokin · Nov 2025Kisspeptin-10: the decapeptide at the top of the reproductive axis
The human decapeptide at the top of the reproductive-axis signalling cascade, and why researchers reach for it. Coming soon to PepNex.
Elena Sorokin · Oct 2025Reconstituting lyophilised research peptides: a handling primer
A bench primer on bringing freeze-dried research peptides into solution: choosing a diluent, adding liquid gently, calculating concentration, aliquoting and cold storage.
PepNex Research · Oct 2025AOD-9604: the tail end of growth hormone, on its own
AOD-9604 is a synthetic fragment of growth hormone's C-terminal region, studied in lipid-metabolism research models. What the preclinical literature actually covers.
Elena Sorokin · Aug 2025Buying research peptides in the UK: how to tell quality from marketing
How UK researchers can separate documented peptide quality from marketing: lot-specific COAs, HPLC purity, mass-spec identity, net peptide content, and certificates you can verify.
PepNex Research · Aug 2025Research peptides and UK rules: research-use-only, and what we choose not to stock
How PepNex decides what to list: the research-use-only framing, why compounds ship as laboratory reagents, UK restrictions, and classes we choose not to stock. Not legal advice.
PepNex Research · Jun 2025CJC-1295 (DAC and no-DAC): a GHRH analogue in two forms
CJC-1295 is a GHRH(1-29) analogue studied in two forms, with and without the albumin-binding DAC linker. A plain-spoken look at what separates them.
Elena Sorokin · Jun 2025Ipamorelin: a selective ghrelin-receptor tool peptide
A synthetic pentapeptide studied as a selective agonist at the ghrelin receptor (GHS-R1a). What the growth-hormone-secretagogue literature examines, and what it doesn't.
Elena Sorokin · Apr 2025Independent testing labs, explained
What a third-party analytical lab does, how HPLC and mass spectrometry differ, and why published, lot-specific certificates matter for research peptides.
PepNex Research · Apr 2025Humanin: the peptide your mitochondria write
A 24-residue peptide encoded in mitochondrial DNA and the first mitochondrial-derived peptide found. What the cytoprotection research looks at.
Elena Sorokin · Mar 2025How to read a certificate of analysis (COA) for research peptides
A plain, practical guide to reading a peptide certificate of analysis: HPLC purity, mass-spec identity, net peptide content, salt form, appearance, lot number and test date.
PepNex Research · Feb 2025ARA-290: erythropoietin's repair signal, minus the red cells
ARA-290 (cibinetide) is an 11-residue peptide built from erythropoietin's helix-B surface, studied as an innate repair receptor agonist. What the research examines.
Elena Sorokin · Jan 2025Thymosin Alpha-1: the thymic peptide and its receptor story
A 28-residue thymic peptide studied for immune signalling through Toll-like receptors. What the research examines, what it doesn't, and the verified molecule.
Elena Sorokin · Nov 2024Epitalon: the four-residue pineal peptide, and what the lab data shows
A four-amino-acid pineal peptide from the Khavinson bioregulator program. What the telomerase and neuroendocrine research actually shows, and where the data stops.
Elena Sorokin · Sept 2024KPV: the small end of alpha-MSH
KPV is the C-terminal tripeptide of alpha-MSH. What in-vitro research examines about PepT1 uptake and NF-kB-linked inflammatory signalling.
Elena Sorokin · Jul 2024GHK-Cu: the copper tripeptide, copper included
GHK-Cu is the copper(II) complex of the tripeptide Gly-His-Lys. What the laboratory literature examines about copper delivery, gene expression and matrix enzymes.
Elena Sorokin · May 2024MOTS-c: a peptide written inside the mitochondrial genome
MOTS-c is a 16-residue mitochondrial-derived peptide. What the preclinical literature examines about AMPK signalling and metabolic regulation.
Elena Sorokin · Mar 2024Selank: tuftsin, rebuilt to last
A heptapeptide analogue of the immune peptide tuftsin, extended with Pro-Gly-Pro. What the preclinical literature examines in GABAergic and monoamine signalling. Research use only.
Elena Sorokin · Feb 2024Dihexa: an angiotensin IV analogue that shrugs off proteases
An N-acylated peptidomimetic built from angiotensin IV, studied as an HGF/c-Met signalling potentiator in preclinical synaptogenesis work. Research use only.
Elena Sorokin · Feb 2024BPC-157 in research: the pentadecapeptide and what the literature actually shows
A synthetic pentadecapeptide (GEPPPGKPADDAGLV) studied in preclinical angiogenesis and cytoprotection models. What the literature shows — and what it doesn't.
Elena Sorokin · Feb 2024Semax: the ACTH fragment engineered to sit still
A synthetic ACTH(4-7) analogue capped with Pro-Gly-Pro for stability. What the preclinical neurochemistry literature examines, and what it does not. Research use only.
Elena Sorokin · Feb 2024TB-500: reading the thymosin beta-4 fragment straight
TB-500 is a synthetic seven-residue fragment of thymosin beta-4. A look at what the preclinical actin-binding and cell-migration literature actually examines.
Elena Sorokin · Jan 2024Peptides in research: a short primer
What a peptide is, how it differs from a protein, how research peptides are made and modified, and how to read the preclinical literature.
Elena Sorokin · Jan 2024