How to reconstitute Glycyl-Histidyl-Lysine-Copper (GHK-Cu)?

GHK-Cu Reconstitution Protocol

GHK-Cu peptide powder should be reconstituted with bacteriostatic water or sterile water at a concentration of 1-2 mg/mL, stored at 2-8°C, and used within 30 days to maintain stability.

Reconstitution Procedure

Materials Required

• Bacteriostatic water (0.9% benzyl alcohol) or sterile water for injection as the reconstitution solvent 1
• Sterile syringe and needle for transfer
• Alcohol swabs for vial preparation
• Refrigerated storage container (2-8°C)

Step-by-Step Reconstitution

Calculate the required volume based on your peptide amount and desired final concentration:

• For a 5 mg vial: add 2.5-5 mL of bacteriostatic water to achieve 1-2 mg/mL concentration 1, 2
• Lower concentrations (1 mg/mL) provide easier dosing accuracy for topical or subcutaneous use

Prepare the vial:

• Allow the lyophilized GHK-Cu powder to reach room temperature (15-20 minutes) before reconstitution
• Wipe the rubber stopper with an alcohol swab and allow to air dry 3

Add the solvent slowly:

• Draw up the calculated volume of bacteriostatic water into a sterile syringe
• Insert the needle at a 45-degree angle into the vial
• Direct the stream of water against the glass wall of the vial, NOT directly onto the powder to prevent foaming and peptide degradation 3
• Add the water slowly over 30-60 seconds

Dissolve the peptide:

• Gently swirl (do NOT shake vigorously) the vial in a circular motion until the powder is completely dissolved 3
• The solution should be clear and colorless when fully reconstituted 2
• If cloudiness persists after 2-3 minutes of gentle swirling, allow the vial to sit at room temperature for 5-10 minutes, then swirl again

Storage and Stability

Refrigerated storage is mandatory:

• Store reconstituted GHK-Cu at 2-8°C (refrigerator temperature) immediately after reconstitution 3, 1
• Never freeze reconstituted peptide solutions as freeze-thaw cycles can denature the peptide structure
• Protect from direct light by storing in the original amber vial or wrapping in aluminum foil

Shelf life considerations:

• Reconstituted GHK-Cu in bacteriostatic water: stable for up to 30 days at 2-8°C 1
• Reconstituted GHK-Cu in sterile water (without preservative): use within 7-10 days due to lack of antimicrobial protection
• Lyophilized (unreconstituted) powder: stable for 12-24 months at -20°C 1, 2

Critical Pitfalls to Avoid

Do not use inappropriate solvents:

• Avoid reconstituting with normal saline, as high salt concentrations can interfere with copper chelation 1
• Do not use tap water or non-sterile water due to contamination risk
• Avoid alcohol-based solutions which can denature the peptide structure

Prevent copper dissociation:

• The copper-peptide complex (GHK-Cu) is pH-sensitive and most stable at pH 7.0-8.0 1, 4
• Exposure to acidic conditions (pH < 6.0) can cause copper dissociation and loss of biological activity
• Do not mix with vitamin C (ascorbic acid) solutions, as the acidic pH will destabilize the complex

Avoid contamination:

• Always use aseptic technique when withdrawing doses from the vial 3
• Do not reuse needles or syringes
• Discard any solution that becomes cloudy, discolored, or contains particulate matter

Concentration Considerations for Different Applications

For topical/cosmetic use:

• Typical concentration: 0.5-2 mg/mL in the final formulation 2, 5
• Can be further diluted in appropriate carrier bases (hyaluronic acid serum, liposomal preparations) 2

For subcutaneous injection (research/clinical use):

• Typical concentration: 1-2 mg/mL 1
• The naturally occurring serum concentration is approximately 200 ng/mL (0.0002 mg/mL) in young adults, declining to 80 ng/mL by age 60 1

Optimal biological activity:

• GHK-Cu demonstrates biphasic dose-response with maximal stimulation at 10⁻⁹ to 10⁻⁸ M concentrations 4
• Higher concentrations may show reduced efficacy compared to optimal dosing range 4

Quality Verification

Visual inspection after reconstitution:

• Solution should be clear and free of particulates 3
• Color should be pale blue (characteristic of copper complexes) or colorless 2
• Any cloudiness, precipitation, or color change indicates degradation or contamination

pH verification (optional but recommended):

• Use pH indicator strips to confirm pH 7.0-8.0 if preparing large batches 6
• Adjust if necessary using small amounts of sterile sodium bicarbonate solution (to raise pH) or sterile acetic acid (to lower pH)