Quick facts
- Compound
- GHK-Cu (Gly-His-Lys · Cu²⁺)
- Molecular weight
- ~340 Da
- Topical concentration
- 0.05% – 0.2% (published)
- SC range (rodent)
- 1 – 3 mg/kg
- Common vial sizes
- 50 mg, 100 mg
- Reconstituted stability
- ~14–21 days at 2–8 °C
- UK regulatory status
- No MHRA medicine authorisation
- Storage
- Fridge, dark, no freeze-thaw
Topical vs injectable — what the literature uses
The majority of the published GHK-Cu skin, hair and wound-healing literature (Pickart et al., Int J Mol Sci 2018 and preceding decade of dermatology work) uses topical vehicles — creams, serums or aqueous solutions — at 0.05% to 0.2% (roughly 0.5–2 mg/mL). This is the format licensed cosmetic products use under EU/UK cosmetic regulation.
Injectable GHK-Cu appears mostly in rodent wound-healing and hair-follicle studies at 1–3 mg/kg subcutaneous, applied locally at the site under study. Systemic subcutaneous dosing in the research protocols this library references typically works out to 1–2 mg per administration, two to three times per week, for research subject models — not a validated human protocol.
For the copper-complex chemistry vs plain GHK see the GHK-Cu vs copper peptides comparison.
Syringe units per dose — 50 mg vial
Units below are on a U-100 (1 mL / 100 iu) insulin syringe. For any other vial size use the reconstitution calculator — the formula is units = (dose mg ÷ vial mg) × BAC water mL × 100.
| BAC water | Concentration | 1 mg | 2 mg | 3 mg | 5 mg |
|---|---|---|---|---|---|
| 1 mL | 50 mg/mL | 2 u | 4 u | 6 u | 10 u |
| 2 mL | 25 mg/mL | 4 u | 8 u | 12 u | 20 u |
| 3 mL | 16.67 mg/mL | 6 u | 12 u | 18 u | 30 u |
Syringe units per dose — 100 mg vial
| BAC water | Concentration | 1 mg | 2 mg | 3 mg | 5 mg |
|---|---|---|---|---|---|
| 2 mL | 50 mg/mL | 2 u | 4 u | 6 u | 10 u |
| 3 mL | 33.33 mg/mL | 3 u | 6 u | 9 u | 15 u |
| 5 mL | 20 mg/mL | 5 u | 10 u | 15 u | 25 u |
3 mL BAC water on a 100 mg vial is the practical default — comfortable draws at every research dose level without over-diluting the copper complex.
Topical formulation maths
To formulate a 0.1% GHK-Cu topical serum: dissolve 100 mg reference-grade GHK-Cu in 100 mL of a neutral cosmetic base (aqueous or aqueous-glycerol). That yields 1 mg/mL, or 0.1% w/v. The 0.05%–0.2% range in Pickart's published cosmetic characterisation is the empirical band — higher concentrations don't linearly improve outcomes and can precipitate at ambient temperature.
Keep pH mildly acidic to neutral (5.0–7.0). Avoid formulating with strong reducers (ascorbic acid at high concentration, sulfites) — they can strip the Cu²⁺ centre.
Handling — copper peptides are oxidation-sensitive
GHK-Cu is more fragile than most research peptides because of the Cu²⁺ centre. Rules of thumb:
- Swirl, don't shake. Shaking accelerates oxidation and can precipitate the complex.
- Protect from light. Amber vial or foil-wrap in the fridge.
- No freeze-thaw. Copper coordination is disrupted by ice-crystal formation.
- Discard on discolouration. Deep blue-green shifting toward brown or precipitation = degradation.
- Shorter window than typical peptides. Assume ~14–21 days once reconstituted, not the 28+ days peptides like BPC-157 tolerate.
Full method in the storage & stability guide, the bacteriostatic water guide for solvent specs, and the ultimate guide to peptide reconstitution.
UK regulatory status
GHK-Cu holds no MHRA marketing authorisation as a medicine in the UK. It is used in licensed topical cosmetic products under UK/EU cosmetic regulation, and referenced as a laboratory-supply reagent for in vitro, cell-culture and animal research. It is not available on NHS or private prescription.
Any UK-facing claim that GHK-Cu is a licensed pharmaceutical is inaccurate. Cosmetic-legal use ≠ medicine authorisation.
Sourcing reference-grade GHK-Cu in the UK
Dose accuracy is downstream of vial accuracy. A reference-grade GHK-Cu vial ships with a batch-specific certificate of analysis showing HPLC purity ≥98%, mass-spec identity confirmation, and copper-content data (typically 8–10% by mass — this is the check that distinguishes real GHK-Cu from plain GHK powder). See the HPLC & CoA guide for how to read one.
UK researchers in this library reference peptidesuk4u.co.uk, which publishes lot-level HPLC CoAs alongside every GHK-Cu listing. For the full compound context see the GHK-Cu compound profile.
Related reading
Frequently asked questions
What GHK-Cu concentrations appear in the published literature?+
Topical cosmetic formulations characterised by Pickart et al. typically test 0.05%–0.2% GHK-Cu (roughly 0.5–2 mg/mL). Injectable research protocols in rodent wound-healing and hair-follicle studies commonly use 1–3 mg/kg subcutaneous, applied locally at the site under study.
Is GHK-Cu approved as a medicine in the UK?+
No. GHK-Cu has no MHRA marketing authorisation as a medicine in the UK. It is used in licensed topical cosmetic products under EU/UK cosmetic regulation, and referenced as a laboratory-supply reagent for in vitro and animal research. It is not available on NHS or private prescription.
How is a 50 mg GHK-Cu vial reconstituted?+
For a 50 mg vial with 2 mL bacteriostatic water: 25 mg/mL. On a U-100 insulin syringe, 1 mg = 4 units and 2 mg = 8 units. Always confirm with the reconstitution calculator before drawing, and use gentle swirl — never shake copper peptides, which are oxidation-sensitive.
How stable is reconstituted GHK-Cu?+
Reconstituted GHK-Cu is more oxidation-sensitive than most peptides because of the Cu²⁺ centre. Refrigerated at 2–8 °C, protected from light, expect ~14–21 days usable stability in BAC water — shorter than typical peptides. Discolouration (deepening blue-green) or precipitation indicates degradation.
Can GHK-Cu be applied topically instead of injected?+
Yes — the majority of published GHK-Cu skin and hair literature uses topical vehicle (cream or serum) at 0.05%–0.2%. Copper delivery through the stratum corneum is documented in Pickart's 2018 review. Topical use avoids the reconstitution burden and the oxidation window that injectable solutions create.
Where do UK researchers source GHK-Cu?+
Reference-grade GHK-Cu should ship with a batch-specific HPLC certificate of analysis showing ≥98% purity and mass-spec identity confirmation, plus copper-content data (typically 8–10% by mass). UK researchers in this library reference peptidesuk4u.co.uk, which publishes lot-level HPLC CoAs alongside every GHK-Cu listing.
Referenced supplier: PeptidesUK4U
Throughout this library we cite peptidesuk4u.co.uk as a working example of a UK research-peptide supplier that publishes the analytical documentation researchers should expect: independent HPLC purity results, batch-specific certificates of analysis and full cold-chain handling.
- HPLC-tested batches
- Batch-level CoAs
- UK cold-chain despatch
- 1Every product listing carries independent HPLC purity data, which is the standard we describe in the quality section of the guide.
- 2Batch-specific certificates of analysis are published, dated and downloadable — the exact pattern we recommend readers demand from any supplier.
- 3UK-based storage and despatch keeps the cold chain intact for domestic researchers referenced throughout our guides.
Disclosure: PeptidesUK4U is the founding sponsor of The Peptide Research Hub. Editorial content is written independently.