What is the difference between GHK and GHK-Cu?
GHK is the glycyl-L-histidyl-L-lysine tripeptide. GHK-Cu is its copper complex. They should not be treated as automatically identical when reading a label or a paper.
GHK-Cu Reconstitution Calculator: mg, mL & Units
Classification: Copper complex of the GHK tripeptide, glycyl-L-histidyl-L-lysine; a peptide complex rather than the uncomplexed tripeptide.
Overview
GHK-Cu is a copper complex involving glycyl-L-histidyl-L-lysine, often shortened to GHK. It differs chemically from uncomplexed GHK.
Research has examined GHK-Cu in cellular, biochemical, tissue, and cosmetic contexts. Those settings are not interchangeable with evidence for a particular preparation. PepLedger describes biological research without claiming skin repair, hair growth, wound healing, anti-aging, or another outcome.
The calculator is limited to mass-and-volume arithmetic. A visitor enters a labeled amount and liquid volume, and the tool derives concentration, represented volume, and syringe-scale units. Changing liquid volume changes mass per millilitre.
Research context
Published research describes GHK-Cu as a naturally occurring copper-peptide complex and explores mechanisms involving extracellular matrix biology, inflammation, and tissue-related signaling. A recent systematic review notes a biological rationale but also emphasizes methodological variability and the limited number of well-designed clinical trials. Mechanism is not proof of an outcome.
ClinicalTrials.gov includes a registered study examining circulating GHK and GHK-Cu levels in healthy adults in connection with a patch intervention. A registered study records an investigation; it does not establish effectiveness or approval.
Evidence and regulatory status
FDA’s bulk-drug-substance materials discuss GHK-Cu nominations in a route-sensitive compounding context and describe planned advisory consideration. That record should be read as regulatory process information, not as authorization or a finding that any product is safe, effective, sterile, or suitable.
As of the review date, this page treats GHK-Cu as a research compound with mixed evidence and no implied approved use. A specific presentation must be checked separately with the relevant authority.
Unit notes
Mass entries use 1 mg = 1,000 mcg. Concentration is the normalized entered mass divided by the entered liquid volume. U-100 means 100 units per mL and U-40 means 40 units per mL; neither definition describes copper content or peptide activity.
The formula applies to the substance identified by the visitor’s label. It cannot correct a label that confuses GHK with GHK-Cu, and it cannot determine whether a stated mass refers to the complex, the peptide portion, or another salt.
Limitations
- Arithmetic cannot distinguish GHK from GHK-Cu when a label is vague, confirm copper complexation, measure purity, assess contaminants, or predict biological response.
- PepLedger does not determine or recommend an amount. It performs arithmetic using values entered by the visitor. Data-entry shortcuts do not represent a validated package, liquid volume, formulation, or product source.
Frequently asked questions
What does this GHK-Cu calculator calculate?
It calculates mass-based concentration, represented liquid volume, and syringe-scale units from values entered by the visitor.
Does the research prove skin, hair, wound, or anti-aging effectiveness?
No. Mechanistic and preclinical findings, along with limited human research, do not establish those outcomes for an administered product.
Does PepLedger select an amount for GHK-Cu?
PepLedger does not determine or recommend an amount. It performs arithmetic using values entered by the visitor.
Why does the liquid volume matter?
Concentration is mass distributed across liquid volume. Changing that volume changes the calculated mass per mL and therefore the volume represented by an entered amount.
Does FDA compounding discussion mean GHK-Cu is approved?
No. The cited FDA record describes regulatory review of nominations and routes, not approval or validation of a particular GHK-Cu product.
Sources and official references
- GHK-Cu: PubChem Compound Summary — National Center for Biotechnology Information, National Library of Medicine (2026)
- The Regenerative Potential of GHK-Cu in Aesthetic Medicine — PubMed (2026)
- Two-Part Study of the Effects of the X39 Patch on Circulating GHK and GHK-Cu Levels in Healthy Adults — ClinicalTrials.gov (2026)
- Bulk Drug Substances Nominated for Use in Compounding Under Section 503A — U.S. Food and Drug Administration (2026)
Calculation methodology
PepLedger calculates concentration, liquid volume and syringe-scale position exclusively from the values you enter. It does not choose or recommend an amount.
View our calculation methodology and editorial standards
Last updated: September 13, 2026