Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

GHK-Cu COA Data Points: Quick Reference Comparison

Purity (%) ≥98% HPLC with UV detection at 220 nm 1 Da deviation or missing entirely Peptide identity, structural integri

This source-based comparison does not add ratings or recommend a winner.

  • Purity (%)
  • ≥98%
  • HPLC with UV detection at 220 nm
  • <95% or missing chromatogram
  • Synthesis byproducts, truncated sequences, degradation
  • Molecular Weight (Da)
  • 340.87 ± 0.5
  • ESI-MS or MALDI-TOF
  • >1 Da deviation or missing entirely
  • Peptide identity, structural integrity, incorrect compound
  • Bacterial Endotoxin (EU/mg)
  • <10 EU/mg
  • LAL (Limulus Amebocyte Lysate) assay
  • >50 EU/mg
  • Gram-negative bacterial contamination from water or synthesis equipment
  • Residual Solvents (ppm)
  • <5000 ppm total
  • GC-MS (gas chromatography-mass spec)
  • >10,000 ppm or solvent not listed
  • Acetonitrile, TFA, methanol left from purification. Skin irritants
  • Heavy Metals (ppm)
  • <10 ppm lead, <20 ppm total
  • ICP-MS (inductively coupled plasma)
  • >30 ppm or testing omitted
  • Lead, cadmium, arsenic. Neurotoxic and carcinogenic contaminants
  • Bottom Line
  • All five sections must pass. One failure disqualifies the batch
  • Third-party lab with ISO 17025 accreditation
  • COA reused from old batch, missing batch number match, or in-house testing only
  • Product safety, dose accuracy, and peptide identity require independent verification