HPLC (High-Performance Liquid Chromatography) is the gold standard for peptide purity verification. Learn what it measures, why 99%+ matters, and how to read a COA.
Written by the Peptide Labs Research Team
HPLC purity is the share of detected material in a peptide sample that is the target peptide, measured by High-Performance Liquid Chromatography. A result of 99% or higher means 1% or less is impurities, such as synthesis by-products, degradation products and residual reagents.
It measures how much of a sample is the target peptide compared with everything else detected. The sample is forced through a column packed with a stationary phase under high pressure, and each compound travels at a different rate. Each one appears as a peak on a chromatogram, and the area under a peak corresponds to that component's percentage of the sample.
Research-grade peptides are held to 99% or higher, because lower-purity material carries more impurities that may interfere with research results or introduce confounding variables.
A complete COA covers purity, identity and batch traceability.
| Element | What to look for |
|---|---|
| HPLC chromatogram | Single dominant peak, minimal impurity peaks |
| Purity | 99% or higher for research grade |
| Retention time | Matches reference standard |
| Mass spectrometry (MS) | Molecular weight matches theoretical |
| Endotoxin (LAL) | <1.0 EU/mg |
| Sterility | Pass |
24 batches in stock · mean 99.21% · lowest 96.5%
| Product | SKU | Batch | HPLC purity |
|---|---|---|---|
| SS-31 10mg | PCUK-SS3110 | 100268 | 99.881% |
| Retatrutide 30mg | PCUK-RT30 | 100236 | 99.831% |
| Retatrutide — Bulk Raw Material | PCUK-RTBULK | 100236 | 99.831% |
| Retatrutide 10mg | PCUK-RT10 | 100234 | 99.682% |
| CJC-1295 (with DAC) 10mg | PCUK-CJCDAC10 | 100279 | 99.643% |
| Retatrutide 20mg | PCUK-RT20 | 100235 | 99.516% |
| Tirzepatide 10mg | PCUK-TIRZ10 | 100269 | 99.512% |
| KPV 10mg | PCUK-KPV10 | 100277 | 99.436% |
| Ipamorelin 10mg | PCUK-IPAM10 | 100273 | 99.395% |
| KLOW Peptide Blend 80mg | PCUK-KLOW80 | 100280 | 99.327% |
| GHK-Cu 100mg | PCUK-GHKCU50 | 100238 | 99.3% |
| TB-500 10mg | PCUK-TB10 | 100272 | 99.205% |
| BPC-157 10mg | PCUK-BPC10 | 100237 | 99.2% |
| Melanotan I 10mg | PCUK-MTI10 | 100254 | 99.2% |
| Selank 10mg | PCUK-SELANK10 | 100243 | 99.2% |
| MOTS-c 10mg | PCUK-MOTS10 | 100276 | 99.153% |
| Semax 10mg | PCUK-SEMAX10 | 100239 | 99.1% |
| Melanotan II 10mg | PCUK-MTII10 | 100240 | 99.1% |
| Epitalon 10mg | PCUK-EPI10 | 100270 | 99.024% |
| Glutathione 1500mg | PCUK-GSH1500 | 100278 | 99.000% |
| BPC-157 + TB-500 Blend 10mg | PCUK-BPCTB10 | 100244 | 99.0% |
| CJC-1295 + Ipamorelin 10mg | PCUK-CJCIPA10 | 100245 | 99% |
| GLOW Peptide Blend 70mg | PCUK-GLOW70 | 100251 | 99.0% |
| Tesamorelin 10mg | PCUK-TESA10 | 100241 | 96.506% |
Some suppliers test in-house, which creates a conflict of interest. Peptide Labs sends every batch to an independent, accredited third-party laboratory, so reporting is unbiased and results are traceable. Only batches that pass all criteria are dispatched, and each COA is published in the COA Library.
Peptide Labs supplies peptides for in-vitro laboratory and research use only. This article is educational content on research quality standards and is not medical advice.
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99%+ HPLC purity · COA verified every batch · Next-day dispatch to Melbourne
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