Guides

Practical, checkable guidance for labs buying research peptides in the UK. Research use only.

• UK research peptide supplier checklistA practical checklist for choosing a UK research peptide supplier: company records, lot-specific CoAs, lab verification, labelling, dispatch, payment and pricing. Research use only.
• Where to buy research peptides in the UKWhere UK labs buy research peptides: specialist UK suppliers, chemical distributors and custom synthesis, with what to check and how to compare prices fairly. Research use only.
• How to read a certificate of analysis (CoA)How to read a research peptide CoA line by line: lot number, lab and task number, HPLC purity, mass spectrometry identity, measured content and what each figure does and does not show.
• UK legal status of research peptides: the factsVerified summary of the UK law that applies to research peptides: the Human Medicines Regulations 2012, the Misuse of Drugs Act 1971 and the Psychoactive Substances Act 2016, each with its source. Not legal advice.
• HPLC and mass spectrometry on a peptide CoA, explainedWhat the HPLC purity figure and the mass spectrometry identity result on a research peptide certificate of analysis actually measure, what they cannot show, and how to check them. Research use only.
• Peptide purity vs net peptide contentWhy a research peptide can be 99% pure by HPLC yet contain less than its labelled weight as peptide: counter-ions such as TFA and acetate, residual water, and how net peptide content is measured. Research use only.
• Handling lyophilised peptides in the lab: receipt to storageA laboratory handling routine for freeze-dried research peptide vials: checking a delivery, recording lot numbers, avoiding moisture uptake, aliquoting and storage. Complements our storage reference data. Research use only.
• UK research peptide prices: October 2026 reportA dated snapshot of UK research peptide prices from Sable's daily price check of 16 October 2026: 60 compounds, 30 UK suppliers checked, Sable vs the cheapest named UK seller at the same mg size.
• Lot numbers and traceability in research peptide supplyWhat a lot (batch) number is, how it links a vial to its synthesis, testing and certificate, and what traceability a lab should expect from a research peptide supplier. Research use only.
• Endotoxin testing for research peptides: LAL and recombinant factor CWhat bacterial endotoxin is, how the LAL and recombinant factor C (rFC) tests detect it, what an EU/mg result on a peptide certificate means, and the limits of each method. Research use only.
• Sterility vs endotoxin vs bioburden: three different testsSterility, bioburden and endotoxin answer different questions about microbial contamination. What each test measures, how it is run, and why research-grade peptide CoAs rarely include all three. Research use only.
• Amino acid analysis: how peptide content is measuredHow amino acid analysis (AAA) quantifies the actual peptide in a lyophilised powder: acid hydrolysis, derivatisation or LC-MS detection, sources of error, and how it relates to net peptide content on a CoA. Research use only.
• Measuring residual TFA in synthetic peptides: ion chromatography and 19F NMRHow laboratories quantify residual trifluoroacetate (TFA) in a synthetic peptide: ion chromatography, 19F NMR and related methods, what the result is expressed as, and why it affects content calculations. Research use only.
• Water content on a peptide CoA: Karl Fischer titration explainedHow residual water in a lyophilised peptide is measured by Karl Fischer titration, coulometric vs volumetric methods, sources of error, and why water content matters for stability and weighing. Research use only.
• Method validation terms on a CoA: specificity, LOD, LOQ, linearity (ICH Q2)Plain definitions of the analytical validation terms that appear on peptide certificates and lab reports, from ICH Q2(R2): specificity, accuracy, precision, linearity, range, LOD and LOQ, and what they tell you about a purity result. Research use only.
• Elemental impurities (ICH Q3D) and synthetic peptidesWhat elemental impurities are, how ICH Q3D classifies them, how ICP-MS and ICP-OES measure them, and where metals can enter peptide synthesis and purification. Research use only.
• ISO/IEC 17025 accreditation: what it means for a peptide testing labWhat ISO/IEC 17025 accreditation covers, how to check a lab's scope, why accreditation is method-specific, and how it differs from a lab simply being independent. Research use only.
• Oxidation-prone residues in peptide solutions: Met, Cys and TrpWhich amino acids make a peptide susceptible to oxidation in laboratory solutions, what the products look like by mass spectrometry, and handling steps that limit oxidation in assays. No dosing; research use only.
• Peptide aggregation in assay solutions: causes and checksWhy some peptides aggregate or self-assemble in laboratory solutions, the conditions that drive it, and practical checks (visual, UV, light scattering, thioflavin T) before an assay. No dosing; research use only.
• Khavinson short peptides: Epitalon, Pinealon, Vilon and Cartalax comparedThe di-, tri- and tetrapeptides known as 'bioregulators': sequences, molecular formulas and masses from PubChem, and the research background of the Khavinson group's work on short peptides and gene expression. Research use only.
• GHRP-2, GHRP-6, hexarelin and ipamorelin: structures comparedThe synthetic growth hormone-releasing peptides side by side: sequences with D-amino acids and non-natural residues, PubChem formulas and masses, and the research history that led to the discovery of ghrelin. Research use only.
• GHRH analogues: sermorelin, CJC-1295 and tesamorelin comparedHow sermorelin, modified GRF(1-29), CJC-1295 with DAC and tesamorelin relate to native growth hormone-releasing hormone: sequence changes, the DAC albumin-binding group, PubChem data and analytical detection. Research use only.
• α-MSH and its analogues: Melanotan I, Melanotan II, PT-141 and KPVHow Melanotan I (afamelanotide), Melanotan II, PT-141 (bremelanotide) and the KPV tripeptide relate to α-melanocyte-stimulating hormone: sequences, cyclisation, PubChem data and research background. Research use only.
• Selank and Semax: tuftsin- and ACTH-derived heptapeptidesSelank and Semax are both short peptides capped with Pro-Gly-Pro. Their sequences, parent peptides (tuftsin and ACTH 4-10), PubChem data and research background, side by side. Research use only.
• Mitochondria-associated peptides: SS-31 and MOTS-c comparedTwo very different peptides studied in mitochondrial research: SS-31, a synthetic cardiolipin-binding tetrapeptide, and MOTS-c, a 16-residue peptide encoded in mitochondrial DNA. Sequences, PubChem data and research background. Research use only.
• UK GH secretagogue and GHRH analogue peptide prices: October 2026UK prices for growth hormone secretagogue and GHRH analogue research peptides from the daily price check of 16 October 2026: Sable vs the lowest other UK listing and the median, same compound and same mg size. Research use only.
• UK bioregulator peptide prices: October 2026UK prices for bioregulator (short peptide) research peptides from the daily price check of 16 October 2026: Sable vs the lowest other UK listing and the median, same compound and same mg size. Epitalon, Pinealon, Thymalin, Vesugen, Vilon, Cartalax. Research use only.
• UK metabolic and mitochondrial research peptide prices: October 2026UK prices for metabolic and mitochondrial research peptides from the daily price check of 16 October 2026: Sable vs the lowest other UK listing and the median, same compound and same mg size. Retatrutide, tirzepatide, cagrilintide, AOD 9604, MOTS-c, SS-31, NAD+, 5-Amino-1MQ, SLU-PP-332. Research use only.
• UK neuropeptide and melanocortin peptide prices: October 2026UK prices for neuropeptide and melanocortin research peptides from the daily price check of 16 October 2026: Sable vs the lowest other UK listing and the median, same compound and same mg size. Selank, Semax, Adamax, DSIP, Dihexa, oxytocin, kisspeptin-10, PT-141, Melanotan I and II. Research use only.
• Tandem mass spectrometry for peptides: b and y ions explainedHow MS/MS fragments a peptide along its backbone, what b and y ions are, how a sequence is read from the ladder of fragment masses, and where the method can mislead. Research use only.
• Charge states and adducts in peptide mass spectra: reading the extra peaksWhy an electrospray mass spectrum of one peptide shows several peaks: multiple charge states, sodium and potassium adducts, TFA clusters and in-source fragments, and how deconvolution turns them into one mass. Research use only.
• Deamidation and isoaspartate in peptides: detection and preventionHow asparagine and glutamine residues deamidate through a succinimide intermediate, why Asn-Gly is the fastest site, how the +0.984 Da change is detected, and handling conditions that slow it. Research use only.
• Pyroglutamate and diketopiperazine: N-terminal cyclisation in peptidesTwo cyclisation reactions that change peptides at the N-terminus: glutamine or glutamate cyclising to pyroglutamate (−17 or −18 Da), and dipeptide loss as a diketopiperazine. Mechanisms, detection and sequences at risk. Research use only.
• Marfey's method: measuring D-amino acid content in a peptideHow chiral purity of a synthetic peptide is actually measured: total hydrolysis, derivatisation with Marfey's reagent (FDAA), HPLC separation of diastereomers, and correcting for racemisation during hydrolysis. Research use only.
• Measuring peptide concentration by UV: A280 vs A205How laboratories estimate peptide concentration in solution from UV absorbance: the A280 method for Trp/Tyr-containing peptides, the A205 method for peptides without them, extinction coefficients and the common errors. No dosing; research use only.
• Nitrogen and CHN analysis: an alternative route to peptide contentHow elemental (CHN) or nitrogen analysis estimates the peptide content of a lyophilised powder, how it compares with amino acid analysis and UV, and when counter-ions skew the result. Research use only.
• HPLC system suitability: resolution, tailing and plate countWhat system suitability tests check before an HPLC purity result is accepted: resolution, tailing factor, theoretical plates, repeatability and signal-to-noise, and what they mean for a peptide chromatogram. Research use only.
• Why peptides elute where they do: RP-HPLC retention and hydrophobicityHow a peptide's sequence determines its retention time on reversed-phase HPLC, hydrophobicity indexes and retention prediction, and why retention time alone is not an identity test. Research use only.
• Isoelectric point (pI) of peptides: calculation and lab useWhat a peptide's isoelectric point is, how it is calculated from pKa values, why different calculators disagree, and how pI guides solvent choice, buffer pH and purification in the lab. No dosing; research use only.
• Residual solvents in synthetic peptides: ICH Q3C classes and GC testingWhich organic solvents are used in peptide synthesis and purification, how ICH Q3C classifies them, how headspace GC measures traces, and what a residual-solvent line on a CoA means. Research use only.
• Forced degradation and stability-indicating methods for peptidesWhat forced degradation (stress testing) is, the conditions used for peptides (acid, base, oxidation, heat, light), how it proves an HPLC method is stability-indicating, and how to read the results. Research use only.
• Stability study terms explained: ICH Q1A conditions, time points and shelf lifeA glossary-style guide to the vocabulary of stability studies from ICH Q1A(R2): long-term, intermediate and accelerated conditions, time points, significant change, retest period and shelf life, applied to lyophilised peptides. Research use only.
• Specification vocabulary from ICH Q6B: characterisation, purity, impurities and potencyA glossary deep dive into the terms ICH Q6B uses for biological products, product-related substances vs impurities, process-related impurities, contaminants, potency, and how they map onto a research peptide CoA. Research use only.
• Reporting, identification and qualification thresholds for impuritiesWhat the three impurity thresholds in ICH Q3A mean, why synthetic peptides are outside its scope, how peptide-specific thresholds differ, and what 'largest single impurity' and 'total impurities' tell you on a CoA. Research use only.
• What happens when a peptide test result is out of specification?How an out-of-specification (OOS) result is investigated: laboratory error checks, retesting rules, why averaging away a failure is not allowed, and what this means for trusting a CoA. Based on FDA OOS guidance. Research use only.
• How precise is a 99% purity result? Measurement uncertainty explainedWhy every analytical result, including HPLC purity, has a measurement uncertainty; how it is estimated (Eurachem/CITAC approach), how to read '99.2% ± 0.3%', and why two labs can report different figures for the same lot. Research use only.
• What is ALCOA+? Data integrity for CoAs and lab recordsThe ALCOA+ principles of data integrity (attributable, legible, contemporaneous, original, accurate, plus complete, consistent, enduring, available), as defined in MHRA guidance, and how they apply to certificates of analysis and lab notebooks. Research use only.
• What is the difference between a retest date and an expiry date?The difference between a retest date, an expiry date and a manufacture or test date on a peptide certificate, how ICH Q7 and Q1A define them, and what a buyer should record. Research use only.
• What are retention samples and why do they matter for lot traceability?What reference and retention (reserve) samples are, how EU GMP Annex 19 and ICH Q7 describe them, how long they are kept, and how they let a disputed lot be re-tested. Research use only.
• What is mean kinetic temperature? Temperature excursions in peptide storage and transitHow mean kinetic temperature (MKT) weights short warm periods more heavily than an arithmetic average, how to calculate it from logger data, and how to judge a temperature excursion during delivery or storage. Research use only.
• Container closure integrity: how a sealed vial keeps a peptide dryWhat container closure integrity (CCI) means for crimped peptide vials, the main test methods (dye ingress, vacuum decay, helium leak, headspace analysis), and the visual checks a lab can make on receipt. Research use only.
• Are peptides light-sensitive? Photostability and ICH Q1B explainedWhich peptide residues are light-sensitive, what ICH Q1B photostability testing requires (1.2 million lux hours and 200 W·h/m² UV), and practical light protection for peptide stocks in the lab. Research use only.
• Do peptide vials need a desiccant? Humidity control in lab storageHow moisture reaches stored lyophilised peptides, when desiccants help, the difference between silica gel and molecular sieves, humidity indicator cards, and the condensation problem with cold vials. Research use only.
• What is the difference between area %, weight % and assay on a peptide CoA?A glossary deep dive into three numbers that are often confused: HPLC area percent (purity), weight percent (content), and assay against a reference standard. What each measures, how they relate, and which to use for concentration. Research use only.
• What is peptide mapping? Enzymatic digestion and LC-MS for longer peptidesHow peptide mapping confirms the sequence of longer peptides and small proteins: enzymatic digestion (trypsin, Glu-C), LC-MS of the fragments, sequence coverage and what a map can and cannot show. Research use only.
• Can NMR check a peptide's identity and purity? qNMR explainedHow 1H NMR complements HPLC and MS for synthetic peptides: structural identity, detecting undeclared constituents, and quantitative NMR (qNMR) purity against an internal standard. Research use only.
• How is peptide aggregation measured? Size-exclusion chromatography explainedHow size-exclusion chromatography (SEC) separates monomer from dimers and higher aggregates, the role of MALS detection, artefacts from column interactions, and when SEC is relevant to peptides. Research use only.
• What does circular dichroism tell you about a peptide?How circular dichroism (CD) spectroscopy estimates α-helix, β-sheet and disordered content of peptides in solution, the characteristic far-UV signatures, analysis software, and practical sample limits. Research use only.
• TFA or formic acid? Mobile-phase additives in peptide LC-MSWhy trifluoroacetic acid gives sharp HPLC peaks but suppresses electrospray MS signal, why formic acid is the usual LC-MS choice, and where difluoroacetic acid fits. What this means for comparing CoA chromatograms. Research use only.
• What are ghost peaks? Carryover and blank injections in peptide HPLCHow carryover from a previous injection, mobile-phase contaminants and gradient artefacts create ghost peaks in peptide chromatograms, why blank injections matter, and how to tell an artefact from a real impurity. Research use only.
• How are HPLC peaks integrated, and how can integration change purity?How chromatography software integrates peaks (baseline drop, valley, tangent skim), why manual reintegration is controlled, and how integration choices move a purity result by tenths of a percent. Research use only.
• What is a relative response factor, and why does it matter for purity?Why HPLC area percent assumes every impurity absorbs UV like the main peptide, how relative response factors (RRFs) correct for it, how they are determined, and when the error is large for peptides. Research use only.
• What does 'mass accuracy 2 ppm' mean? High-resolution MS for peptide identityHow high-resolution mass spectrometry confirms a peptide's elemental formula: ppm mass error, resolving power, isotope patterns and the monoisotopic peak, and how to read an observed-vs-theoretical mass line on a CoA. Research use only.
• What is the difference between GLP, GMP and ISO/IEC 17025?Three quality frameworks that are often confused: GLP for non-clinical safety studies, GMP for manufacturing medicines and APIs, and ISO/IEC 17025 for testing-lab competence. What each covers, who inspects it in the UK, and which applies to a research peptide CoA. Research use only.
• CoA vs CoC: what must a certificate of analysis contain under ICH Q7?A certificate of analysis reports measured test results for one lot; a certificate of conformance only states that a product meets a specification. How to tell them apart, what ICH Q7 expects on a CoA, and why it matters for research peptides. Research use only.
• How do you send a peptide sample for independent testing?A practical guide to commissioning an independent HPLC/MS test of a research peptide: choosing an accredited lab, chain-of-custody records, sample amount, packing, and reading the report against the supplier's CoA. Research use only.
• What should a research peptide vial label show?The information a research peptide vial label should carry: compound name, stated amount, printed lot number, storage condition and research-use statement, how it links to the CoA, and how ICH Q7 approaches labelling and traceability. Research use only.
• What is lot genealogy? Batch records and traceability explainedHow batch records and lot genealogy trace a finished peptide lot back through purification, synthesis and raw-material lots, and forward to every vial sold, with ICH Q7 definitions and what a research buyer can reasonably ask. Research use only.
• How to verify a peptide CoA and spot signs of alterationPractical document checks for a research peptide certificate: lot-number match, lab identity and verification, internal consistency of masses and dates, chromatogram plausibility, and when to request confirmation from the issuing lab. Research use only.
• Should peptides be stored at −20 °C or −80 °C?How −20 °C and −80 °C storage compare for lyophilised peptides and peptide solutions, why frost-free freezers cycle temperature, door and alarm practice, and how to choose for a research lab. Research use only.
• Do lyophilised peptides need cold shipping? Ambient, cold packs and dry ice comparedWhen lyophilised peptides can travel at ambient temperature, when cold packs or dry ice are used, dry ice as a dangerous good (UN 1845), and what to check on arrival. Research use only.
• How should peptide stock solutions be aliquoted and recorded?Why and how to divide a peptide stock solution into single-use aliquots: choosing volumes, tubes, labelling, freezing, records linking each aliquot to the vial's lot number, and when to discard. No dosing; research use only.
• Why does freezing change the pH of a peptide solution?How buffer components crystallise during freezing and shift pH (notably sodium phosphate), how freeze-concentration drives aggregation and degradation, and which buffers and practices reduce freeze–thaw damage. Research use only.
• Which syringe filter should be used for a peptide solution?How membrane material (PES, PVDF, nylon, cellulose acetate) affects peptide loss by adsorption during filtration, pore sizes, pre-rinsing and how to check recovery. No dosing; research use only.
• Which buffer should a peptide assay solution use?How to choose a buffer for peptide research solutions: pKa and buffering range, temperature and freezing behaviour, metal and phosphate interactions, compatibility with LC-MS, and a comparison table of common buffers. Research use only.
• When is DMSO used to dissolve peptides, and what are the risks?Why DMSO is used for hydrophobic peptides and compound libraries, its hygroscopicity and freezing point (18.5 °C), oxidation risk for cysteine and methionine, water uptake and freeze–thaw effects on stored stocks. Research use only.
• What is the difference between hygroscopic and deliquescent?Definitions of hygroscopic, deliquescent, efflorescent and critical relative humidity, why lyophilised peptides are hygroscopic, how moisture uptake affects weighing and stability, and practical handling. Research use only.
• Why does a peptide's molecular weight differ between the salt and free base?How counter-ions such as acetate, TFA and hydrochloride add to a peptide's formula weight, how to convert between salt and free-base mass, and why CoAs, PubChem and mass spectra can show different numbers. Research use only.
• What are lyoprotectants and bulking agents in freeze-dried peptides?Definitions of lyoprotectant, cryoprotectant, bulking agent, cake collapse, glass transition (Tg′) and residual moisture, with common excipients such as trehalose, sucrose and mannitol, and why many research peptides are supplied without excipients. Research use only.
• How to verify a CoAConfirm a certificate with the testing lab using its task number and verification key.
• Reconstitution concentration calculatorPeptide mass and solvent volume to concentration in mg/mL.
• CoA libraryPublished lab certificates by lot.