[{"data":1,"prerenderedAt":325},["ShallowReactive",2],{"article-\u002Fresearch\u002Fhow-to-read-a-peptide-coa":3,"article-compounds-\u002Fresearch\u002Fhow-to-read-a-peptide-coa":288,"article-more-\u002Fresearch\u002Fhow-to-read-a-peptide-coa":310},{"id":4,"title":5,"body":6,"description":258,"extension":259,"faq":260,"meta":270,"navigation":271,"path":272,"publishedAt":273,"readingMinutes":274,"relatedCompounds":275,"seo":279,"stem":280,"tags":281,"updatedAt":286,"__hash__":287},"research\u002Fresearch\u002Fhow-to-read-a-peptide-coa.md","How to Read a Peptide Certificate of Analysis",{"type":7,"value":8,"toc":245},"minimark",[9,13,16,21,29,32,35,41,45,48,51,56,60,63,69,72,84,90,96,101,105,117,120,127,132,136,139,146,153,157,168,171,175,178,193,196,200,222,225,229,237],[10,11,12],"p",{},"Every vial of research peptide arrives with a document that looks authoritative:\nletterhead, a chromatogram, a percentage with a decimal place, a signature.\nMost researchers glance at the purity figure and file it.",[10,14,15],{},"The purity figure is not the most useful thing on the page, and on a\npoorly-constructed certificate it is often the only thing that has been thought\nabout. This is a walkthrough of what each field is doing, in rough order of how\nmuch weight it can actually bear.",[17,18,20],"h2",{"id":19},"_1-batch-or-lot-number-the-field-everything-else-depends-on","1. Batch or lot number — the field everything else depends on",[10,22,23,24,28],{},"A Certificate of Analysis is a record of tests performed ",[25,26,27],"strong",{},"on one specific batch\nof material",". Not on the product line, not on a representative sample from last\nyear, not on the compound in general. On a batch.",[10,30,31],{},"The batch number is what ties the document to the vial in your hand. If the\nnumber on the certificate does not appear on the vial label, the certificate is\ndescribing some other material, and nothing else on it is evidence about yours.",[10,33,34],{},"This is the single most common defect in research peptide documentation, and\nit is not usually subtle. A \"COA\" downloaded from a product page with no batch\nnumber, or with a batch number that changes nothing when the stock does, is a\nmarketing asset formatted as a laboratory document.",[10,36,37,40],{},[25,38,39],{},"What to check:"," the batch number exists, it appears on the vial, and the two\nmatch.",[17,42,44],{"id":43},"_2-product-name-and-sequence","2. Product name and sequence",[10,46,47],{},"The certificate should state what was supposed to be made, unambiguously. For a\npeptide, that means the sequence in single- or three-letter code, not only a\ntrade name.",[10,49,50],{},"Sequence matters here because names in this market are unreliable. \"TB-500\" is\napplied to both full-length thymosin β4 (43 residues, ~4,963 Da) and to the\nAc-LKKTETQ fragment (7 residues, ~889 Da). \"CJC-1295\" is applied to both the DAC\nand non-DAC forms, which differ by roughly 280 Da and behave differently. A\nsequence removes the ambiguity that a name preserves.",[10,52,53,55],{},[25,54,39],{}," a sequence is stated, and it is the sequence you ordered.",[17,57,59],{"id":58},"_3-hplc-purity-what-the-percentage-actually-measures","3. HPLC purity — what the percentage actually measures",[10,61,62],{},"High-performance liquid chromatography separates the components of a sample and\na detector records them as they elute. The output is a trace of peaks against\nretention time. Purity is reported as:",[64,65,66],"blockquote",{},[10,67,68],{},"the area of the main peak, divided by the total integrated area of all peaks,\nexpressed as a percentage.",[10,70,71],{},"Three things follow from that definition, and all three are routinely\nmisunderstood.",[10,73,74,77,78,83],{},[25,75,76],{},"It is relative, not absolute."," 99% means the main peak accounts for 99% of\neverything the detector saw. It does not mean the vial is 99% peptide by mass —\nwater and counter-ion salt are invisible to a UV detector and sit entirely\noutside the figure. See\n",[79,80,82],"a",{"href":81},"\u002Fresearch\u002Fnet-peptide-content-vs-purity","net peptide content versus purity",".",[10,85,86,89],{},[25,87,88],{},"It depends on the detection wavelength."," Peptide work typically detects around\n214 nm, where the peptide bond absorbs. A method run at 280 nm sees only aromatic\nresidues, and any impurity lacking them becomes invisible — which flatters the\nnumber.",[10,91,92,95],{},[25,93,94],{},"It depends on where the integration boundaries were drawn."," A deletion\nsequence eluting close to the main peak can be integrated separately or absorbed\ninto it, and the difference between those two choices can be a full percentage\npoint. This is why the chromatogram is worth more than the number extracted from\nit.",[10,97,98,100],{},[25,99,39],{}," the wavelength and the method are stated, and the chromatogram\nis included rather than described.",[17,102,104],{"id":103},"_4-mass-spectrometry-the-field-that-answers-a-different-question","4. Mass spectrometry — the field that answers a different question",[10,106,107,108,112,113,116],{},"HPLC answers ",[109,110,111],"em",{},"how much of this material is one thing",". Mass spectrometry answers\n",[109,114,115],{},"what that thing is",". They are separate questions and a certificate that\naddresses only the first has done half the job.",[10,118,119],{},"The instrument ionises the sample, measures mass-to-charge ratios, and the\nobserved molecular mass is compared against the theoretical mass calculated from\nthe intended sequence. A match within tolerance establishes identity. A mismatch\nof one residue's worth — anywhere from 57 Da for glycine to 186 Da for\ntryptophan — is a deletion sequence, and those are precisely the impurities\nchromatography is worst at separating.",[10,121,122,123,126],{},"A certificate should state ",[25,124,125],{},"both"," the theoretical and the observed mass. Only\none of them is a result; the other is arithmetic. Showing both is what lets a\nreader check the comparison rather than take it on trust.",[10,128,129,131],{},[25,130,39],{}," theoretical mass, observed mass, and that they agree.",[17,133,135],{"id":134},"_5-appearance","5. Appearance",[10,137,138],{},"Usually dismissed as boilerplate — \"white lyophilised powder\" — and usually it\nis. But it is the one field a reader can verify without an instrument, and there\nare compounds where it carries real information.",[10,140,141,142,145],{},"GHK-Cu should be ",[25,143,144],{},"blue",". It is a copper(II) complex and the colour comes from\nthe coordinated metal. White powder sold as GHK-Cu is either the uncomplexed\ntripeptide or something else.",[10,147,148,149,83],{},"For everything else, appearance is a cake-condition report. A collapsed,\nshrunken or discoloured cake indicates a lyophilisation cycle that went wrong or\na temperature excursion in storage — either of which has already affected the\nmaterial regardless of what the purity figure says. See\n",[79,150,152],{"href":151},"\u002Fresearch\u002Fwater-content-and-lyophilisation-quality","water content and lyophilisation quality",[17,154,156],{"id":155},"_6-date-of-analysis","6. Date of analysis",[10,158,159,160,163,164,167],{},"Two dates matter and certificates often show only one. The ",[25,161,162],{},"date of manufacture","\ntells you how old the material is. The ",[25,165,166],{},"date of analysis"," tells you how old the\ndata is. A certificate dated two years before the vial was filled describes the\nmaterial as it was, not as it is.",[10,169,170],{},"Peptides degrade slowly when stored correctly, which is exactly what makes a\nstale certificate plausible enough to pass unnoticed.",[17,172,174],{"id":173},"_7-what-is-not-on-a-peptide-coa","7. What is not on a peptide COA",[10,176,177],{},"Worth being explicit, because absence is often read as a pass.",[10,179,180,181,184,185,188,189,192],{},"A standard peptide certificate says nothing about ",[25,182,183],{},"sterility",", nothing about\n",[25,186,187],{},"endotoxin content",", and nothing about ",[25,190,191],{},"residual solvents"," unless those tests\nare listed on it. These are separate analyses using entirely different methods.",[10,194,195],{},"Nor does it make any statement about safety, suitability, or behaviour in any\nbiological system. It is a chemistry document describing a chemical.",[17,197,199],{"id":198},"a-practical-order-of-operations","A practical order of operations",[201,202,203,207,210,213,216,219],"ol",{},[204,205,206],"li",{},"Batch number on the certificate matches the vial. If not, stop.",[204,208,209],{},"Sequence stated and correct.",[204,211,212],{},"Observed mass matches theoretical mass.",[204,214,215],{},"Purity figure accompanied by a chromatogram, a wavelength and a method.",[204,217,218],{},"Appearance consistent with what you received.",[204,220,221],{},"Analysis date close to the manufacture date.",[10,223,224],{},"Anything that fails at step one makes the rest moot, which is why it is step one.",[17,226,228],{"id":227},"what-this-catches-and-what-it-does-not","What this catches, and what it does not",[10,230,231,232,236],{},"This process catches missing documentation, mismatched material, substituted\ncompounds, stale data and the fabricated certificates that are common enough to\nbe worth assuming — ",[79,233,235],{"href":234},"\u002Fresearch\u002Fspotting-a-fabricated-coa","what forged COAs get wrong","\ncovers the tells.",[10,238,239,240,244],{},"It does not catch a competent forgery of a real document, and it does not\nsubstitute for an independent result from a laboratory with no interest in the\nsale. That is what\n",[79,241,243],{"href":242},"\u002Fresearch\u002Fthird-party-testing-explained","third-party verification is for",", and\nwhy it is worth understanding what the phrase does and does not mean when a\nvendor uses it.",{"title":246,"searchDepth":247,"depth":247,"links":248},"",2,[249,250,251,252,253,254,255,256,257],{"id":19,"depth":247,"text":20},{"id":43,"depth":247,"text":44},{"id":58,"depth":247,"text":59},{"id":103,"depth":247,"text":104},{"id":134,"depth":247,"text":135},{"id":155,"depth":247,"text":156},{"id":173,"depth":247,"text":174},{"id":198,"depth":247,"text":199},{"id":227,"depth":247,"text":228},"A field-by-field walkthrough of a peptide COA — what each number establishes, which fields are load-bearing, and what a missing batch number tells you about the rest of the document.","md",[261,264,267],{"question":262,"answer":263},"What is the most important field on a peptide Certificate of Analysis?","The batch or lot number. Every other figure on the document describes one specific batch of material, and without a batch number that matches the vial label there is no way to establish that the certificate describes what you received. A COA with no batch number is a brochure.",{"question":265,"answer":266},"Is 99% purity better than 98%?","Not necessarily, and treating it as a ranking is a common error. The figure is the main peak's share of total integrated peak area, and it depends on the detection wavelength, the gradient, and where the analyst set the integration boundaries. A well-documented 98% from a method you can see beats an undocumented 99.9% from one you cannot.",{"question":268,"answer":269},"Does a Certificate of Analysis prove the peptide is safe?","No. A peptide COA addresses purity and identity. It does not address sterility, endotoxin content, or residual solvents unless those tests are explicitly listed on it — and it makes no statement at all about safety in any biological system. These are research chemicals and the certificate is a chemistry document.",{},true,"\u002Fresearch\u002Fhow-to-read-a-peptide-coa","2026-08-18",9,[276,277,278],"retatrutide","tb-500","bpc-157",{"title":5,"description":258},"research\u002Fhow-to-read-a-peptide-coa",[282,283,284,285],"COA","HPLC","mass spectrometry","quality control",null,"t572-3d09yX5rsoW2XZzSP_1pQ5dG1--altqRLiH8Tw",[289,297,304],{"path":290,"name":291,"alsoKnownAs":292,"summary":293,"category":294,"molecularWeight":295,"purity":296},"\u002Fcompounds\u002Fbpc-157","BPC-157","Body Protection Compound 157 · PL 14736","A synthetic 15-amino-acid sequence derived from human gastric juice protein BPC, studied extensively in tissue repair and angiogenesis models.","Repair & Recovery","~1,419.5 Da","≥99%",{"path":298,"name":299,"alsoKnownAs":300,"summary":301,"category":302,"molecularWeight":303,"purity":296},"\u002Fcompounds\u002Fretatrutide","Retatrutide","LY3437943","A single-molecule GLP-1, GIP and glucagon receptor triple agonist, the third generation of incretin-based metabolic research peptides.","Metabolic","~4,731 Da",{"path":305,"name":306,"alsoKnownAs":307,"summary":308,"category":294,"molecularWeight":309,"purity":296},"\u002Fcompounds\u002Ftb-500","TB-500","Thymosin β4 · Tβ4","A synthetic form of thymosin beta-4, the principal actin-sequestering peptide in mammalian cells, studied in cell migration and tissue repair models.","~4,963 Da",[311,316,321],{"path":312,"title":313,"description":314,"publishedAt":315},"\u002Fresearch\u002Fchoosing-a-peptide-supplier-australia","Choosing a Research Peptide Supplier in Australia: A Checklist","Fourteen questions that separate suppliers with a real quality process from suppliers with a good website — covering documentation, testing claims, provenance, handling and the language they use.","2026-08-24",{"path":317,"title":318,"description":319,"publishedAt":320},"\u002Fresearch\u002Fcounterfeit-peptides-australia","Counterfeit and Substituted Research Peptides: What Actually Gets Faked","Substitution, dilution, wrong-form supply and underfilled vials — the four ways research peptides are misrepresented, why each is hard to detect, and which analytical test catches which.","2026-08-23",{"path":322,"title":323,"description":324,"publishedAt":320},"\u002Fresearch\u002Fresearch-peptides-australia-legal-status","Research Peptides in Australia: The Regulatory Position","How the TGA, the Poisons Standard and import rules apply to peptides supplied for laboratory research in Australia — what research-use-only means legally, and where the line sits.",1787473952615]