Supplied for research purposes only. These peptides are laboratory reagents intended for qualified researchers and educational institutions. Not for human use, animal use, or clinical application.
GHK-Cu Storage & Stability Datasheet
🖨️ NovaVitality Technical Datasheet
Document ID: NV-DS-GHKCU-001
Version: 1.0
Effective Date: 10 December 2025
Product: GHK-Cu Research Peptide (RUO)
1. Product Overview
| Parameter | Specification |
| INN (Proposed) | GHK-Cu (Glycyl-L-Histidyl-L-Lysine–Copper(II)) |
| CAS Status | 40949-98-6 (assigned) |
| Molecular Formula | C₁₄H₂₄CuN₆O₄ |
| Molecular Weight | 412.93 g/mol (monoisotopic, Cu-63 dominant) |
| Sequence | H-Gly-His-Lys-OH • Cu²⁺ (1:1 square-planar complex) |
| Receptor Profile | Receptor-independent; modulates MMPs, TGF-β, Nrf2, collagen genes via Cu-dependent redox signalling |
| Form Supplied | Lyophilised solid (pale blue to violet powder — colour confirms Cu²⁺ coordination) |
| Purity (HPLC-UV) | ≥98% (dual-wavelength: 220 nm peptide + 525 nm Cu-d-d transition) |
| Cu:Peptide Ratio | 0.95–1.05 (atomic absorption spectroscopy, AAS) |
| Endotoxin | <0.1 EU/mg (LAL kinetic assay — ultra-low for metallopeptides) |
| Residual Solvents | Meets ICH Q3C Class 3 limits |
| RUO Status | For research use only — not for human, veterinary, cosmetic, or diagnostic use |
2. Recommended Storage Conditions
✅ Unopened (Lyophilised)
| Condition | Stability Duration | Notes |
| −20°C, desiccated, dark, argon-flushed vial | ≥24 months | Optimal — preserves Cu²⁺ oxidation state. Violet colour remains stable. |
| 2–8°C (refrigerated) | ≤6 months | Acceptable for active use; monitor for colour fade (→ pale pink = partial reduction). |
| Room Temp (≤25°C) | ≤7 days | For transit only. Avoid light — UV accelerates Cu reduction. |
📌 GHK-Cu is sensitive to redox environment — lyophilisation under inert gas is critical. NovaVitality uses argon headspace in all vials.
✅ Reconstituted (Solution)
| Solvent | Short-Term (2–8°C, dark) | Long-Term (−80°C, dark) | Notes |
| Ultrapure H₂O (18.2 MΩ·cm) | ≤72 hours | ≤3 months (aliquoted) | Preferred — minimal ion interference |
| Sterile PBS (pH 7.4) | ≤48 hours | ≤2 months (aliquoted) | Acceptable; avoid Tris (chelates Cu) |
| Cell Culture Media (e.g., DMEM) | ≤24 hours | Not recommended | Serum proteins and ascorbate reduce Cu²⁺ → loss of activity |
⚠️ Critical:
– Do not freeze in glass — alkaline leachates promote Cu dissociation. Use polypropylene only.
– Limit freeze–thaw to ≤2 cycles — each thaw increases Cu⁺ fraction (detectable by loss of 525 nm absorbance).
– For in vivo studies: prepare daily working solutions from −80°C stock.
3. Stability Indicators & Degradation Risks
| Risk Factor | Effect on GHK-Cu | Detection Method |
| Light exposure (UV/visible) | Cu²⁺ → Cu⁺ reduction; complex dissociation | UV-Vis: ↓A₅₂₅, ↑A₂₉₀ (free GHK), colour fade (violet → pink/colourless) |
| Reducing agents (ascorbate, DTT) | Irreversible Cu stripping → apo-GHK | LC-MS: 372.2 Da peak (GHK), loss of 412.9 Da; AAS: ↓Cu content |
| Chelators (EDTA, citrate) | Competitive Cu binding → inactive complex | ICP-MS: Cu shift to supernatant; bioassay loss (collagen I in fibroblasts) |
| Alkaline pH (>8.0) | His deprotonation → coordination loss | HPLC peak splitting; ↓A₅₂₅ |
| Oxygen & moisture | Slow oxidation → dityrosine crosslinks (if Lys-modified) | SEC-HPLC: high-MW aggregates |
🔬 Tip: Validate complex integrity pre-assay: measure A₅₂₅/A₂₂₀ ratio — should be ≥0.15 for >95% occupancy.
4. Reconstitution Protocol (Best Practice)
- Equilibrate vial to room temp (10 min) in dark.
- Centrifuge briefly (3 sec) to collect powder.
- Add ultrapure water slowly down vial wall (e.g., 1 mL for 10 mg → 10 mM stock).
- Gently swirl — do not vortex, pipette vigorously, or sonicate.
- Confirm faint blue/violet colour persists.
- Filter through 0.22 µm PVDF (low metal-binding membrane).
- Aliquot into pre-chilled polypropylene tubes, seal, wrap in foil, and flash-freeze at −80°C.
5. Analytical Verification (Post-Storage)
| Test | Acceptance Criteria | When to Run |
| UV-Vis (A₅₂₅) | A₅₂₅/A₂₂₀ ≥ 0.15 | Before every critical assay |
| HPLC Purity | ≥95% main peak (220 & 525 nm) | After >3 months storage |
| AAS (Cu:peptide) | 0.90–1.10 | Annually or after suspected contamination |
| Bioactivity (Optional) | ≥90% collagen I induction vs. CoA (NHDFs, 72h, 1 µM) | For publication or longitudinal studies |
6. References & Compliance
- Pickart L. Biochem Biophys Res Commun. 1980;94(1):100–106. DOI: 10.1016/0006-291X(80)91494-2
- Bissett DL et al. J Cosmet Dermatol. 2008;7(1):30–39. DOI: 10.1111/j.1473-2165.2007.00357.x
- ICH Q1A(R2): Stability Testing
- USP <1058>: Analytical Instrument Qualification (for AAS/UV-Vis)
- MHRA Guidance on Metal-Containing Research Substances (2024)
7. Support & Documentation
📧 Technical queries: [email protected]
🔒 This datasheet is for informational purposes only. NovaVitality makes no warranties regarding fitness for purpose. Researchers are solely responsible for validation in their experimental systems.
