Understand the source comparison
Glow Stack COA: Testing Method Comparison
HPLC (High-Performance Liquid Chromatography) Purity percentage. Proportion of powder that is target peptide vs impurities ≥98% for research-grade; 95–97.9% usable with dose adjustment Determines active dose per mg and reproducibility across protocols The sing
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This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- HPLC (High-Performance Liquid Chromatography)
- Purity percentage. Proportion of powder that is target peptide vs impurities
- ≥98% for research-grade; 95–97.9% usable with dose adjustment
- Determines active dose per mg and reproducibility across protocols
- The single most important number on any COA. Below 95% is non-negotiable rejection
- Mass Spectrometry (MS)
- Molecular weight confirmation
- Observed MW within ±1 Dalton of expected MW
- Confirms peptide identity at molecular level; catches synthesis errors HPLC cannot detect
- Without MS verification, you're trusting the label. Not testing the contents
- Concentration (Net Peptide Content)
- Actual peptide quantity per vial in mg
- Stated amount ±5% (e.g., 5mg vial should contain 4.75–5.25mg)
- Determines reconstitution math and dose accuracy
- Underfilled vials cascade into systematic underdosing across the entire research period
- Appearance/Solubility (Visual Inspection)
- Colour, particle size, reconstitution behaviour
- White to off-white powder; clear solution after reconstitution
- Detects gross contamination or degradation not measurable by HPLC/MS
- Subjective but fast. Discoloured powder or cloudy reconstitution is immediate rejection