GHK-Cu 50mg

What is GHK-Cu ?

GHK-Cu 50mg is the smaller vial of GHK-Cu, the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, also called copper tripeptide-1. It holds half the lyophilised powder of the 100mg vial, about 124 µmol of complex, as a blue powder.

The compound is identical in both vial sizes. Its copper transport role, its matrikine origin in type I collagen and the matrix and gene-expression literature are covered on the main GHK-Cu page. What differs at 50mg is the in-use window and the molar arithmetic.

GHK-Cu Research Applications

The research uses match the 100mg vial: copper transport to copper-dependent enzymes, extracellular matrix biology such as collagen, glycosaminoglycan and matrix metalloproteinase-2 expression, and transcriptomic profiling. The 50mg vial is most useful for small-scale work that depends on an intact complex. Examples are spectrophotometry of the Cu(II) centre, stability studies across buffers, competition experiments with other chelators and method development for HPLC or ICP analysis.

GHK-Cu 50mg vs 100mg: Which Vial Size to Choose

Both vials hold the same complex, so the choice is about handling and cost. GHK-Cu is light-sensitive, and freeze-thaw can disturb the copper binding as well as the peptide. A 50mg vial is used up sooner, so one reconstituted stock sees fewer stopper punctures, less light and fewer freeze-thaw cycles. That suits pilot studies, method development, spectrophotometric work and any protocol that will not use 100mg promptly. The 100mg vial costs less per milligram, and one batch and certificate cover twice the work. Molar content is about 124 µmol against about 248 µmol.

Research Overview

This page covers the 50mg presentation of GHK-Cu, the copper(II) complex of glycyl-L-histidyl-L-lysine, molecular formula C₁₄H₂₄CuN₆O₄, molecular weight 403.9 g/mol, CAS 89030-95-5. The compound is identical to that in the 100mg vial, and the copper-shuttle model, matrikine classification and extracellular matrix literature are set out on the main GHK-Cu page. What this page addresses is what changes at half the vial content. The choice between 50mg and 100mg is mostly a question of in-use exposure rather than economy. GHK-Cu is a photolabile copper(II) complex, and freeze-thaw cycling can disrupt the copper coordination sphere independently of any damage to the peptide backbone. A 50mg vial is consumed across a shorter working life, which means fewer stopper penetrations, less cumulative light exposure and fewer freeze-thaw cycles on one reconstituted stock. For pilot studies, method development, or any protocol that will not consume 100mg inside a sensible in-use window, the smaller vial is the technically preferable choice rather than merely the cheaper one. The 100mg vial wins on cost per milligram and on batch continuity across a larger body of work. One arithmetic point is specific to this size, where a proportional error is easy to overlook. Molar calculations must use the mass of the complex, 403.9 g/mol, and not the free tripeptide at 340.4 g/mol. A 50mg vial of GHK-Cu therefore contains approximately 124 µmol of complex, whereas computing against the copper-free tripeptide would return roughly 147 µmol and overstate the figure by about 19 percent.

Storage and Reconstitution

Keep sealed vials at -20°C, away from light and moisture. After reconstitution, keep the solution at 2-8°C in a light-proof container and use it within 4 weeks. Freeze-thaw can disturb the copper binding, so store single-use aliquots in amber or foil-wrapped vials at -20°C.

Vials are sold on their own, without bacteriostatic water for mixing or other supplies.

How to reconstitute and handle

Let the vial and the bacteriostatic water reach room temperature and swab both stoppers with alcohol. Add the water slowly down the inside wall of the vial, away from direct light, and swirl gently until the blue colour is even. Do not shake or vortex. A blue to blue-violet solution is expected. A colourless or green-tinged one means the complex has been disrupted, which absorbance at around 500 to 600 nm will confirm. Use glass or good polypropylene labware, not stainless steel, which can strip copper from the peptide.

• Use 403.9 g/mol, the mass of the copper complex, for any molar calculation on this vial. Substituting the free tripeptide mass of 340.4 g/mol overstates the molar content of a 50mg vial by roughly 19 percent.
• Protect from light throughout handling. Copper(II) peptide complexes are photolabile, and reconstitution should be carried out away from direct light with aliquots transferred to amber or foil-wrapped vessels.
• Confirm the blue to blue-violet colour on reconstitution. A colourless or green-tinged solution indicates the complex has been disrupted rather than simply diluted. Visible absorption spectrophotometry around 500-600 nm is the standard bench check on complex integrity.
• Use glass or high-grade polypropylene labware and avoid prolonged contact with stainless steel or other chelating surfaces that can strip Cu(II) from the tripeptide. Strong chelators, phosphate-rich buffers and reducing agents in the experimental medium will compete for the copper centre.
• Prefer single-use aliquots to repeated access of one stock. Freeze-thaw cycling can disrupt the copper coordination sphere as well as degrade the peptide backbone. The shorter working life of a 50mg vial is part of its advantage over the 100mg presentation, so avoid extending it unnecessarily.

For the full method, see the peptide reconstitution guide and the reconstitution calculator.

Research References

• Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells (Nature, 1980)
• GHK-Cu stimulates matrix metalloproteinase-2 expression by fibroblast cultures (Life Sci, 2000)
• GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration (Biomed Res Int, 2015)

Published research on GHK-Cu is indexed on PubMed. See our full UK buyer's guide for GHK-Cu, UK buyer's guide for GHK-Cu 50mg and UK buyer's guide for GHK-Cu CoA.