GHK-Cu Reconstitution Calculator

Mixing GHK-Cu: What to Know Before You Reconstitute

1. 01

   Bacteriostatic water vs. sterile water

   Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth once the vial has been punctured, and it is the standard choice for a vial drawn from repeatedly. Sterile water has no preservative and is generally treated as single use. Because GHK-Cu vials are large and typically last a long time relative to the amount used per draw, the multi week service life makes bacteriostatic water the usual choice. The larger vial size also means more punctures over the life of the vial than with a small peptide vial.

2. 02

   How much water to add

   The water volume sets concentration, not content. A 50 mg vial holds 50 mg whether you add 2 mL or 10 mL. GHK-Cu differs from smaller peptides in that the vial contains far more material, so at low water volumes the solution becomes very concentrated and draws become extremely small. Higher water volumes are common for this reason.

   Vial	Water	Concentration	Per unit	1 mg draw	2 mg draw
   50 mg	5 mL	10.0 mg/mL	100 mcg	10 units	20 units
   50 mg	10 mL	5.0 mg/mL	50 mcg	20 units	40 units
   100 mg	10 mL	10.0 mg/mL	100 mcg	10 units	20 units
   100 mg	20 mL	5.0 mg/mL	50 mcg	20 units	40 units

   One practical constraint appears in this table that does not come up with 5 mg vials: the water volumes involved often exceed what a single vial can physically hold. A 50 mg vial may not have room for 10 mL, in which case people either use a lower volume or transfer to a larger sterile vial. Check the vial's capacity before committing to a volume, and use the calculator above to see what a given volume does to your draw size.

3. 03

   Mixing technique

   Run the water down the inside wall of the vial rather than directly onto the powder, then swirl gently until dissolved. Do not shake. The resulting solution should be clear and blue, which is normal and comes from the copper in the compound. A blue tint is not a sign of contamination. What people do look for is clarity: visible particles or cloudiness after gentle swirling is the same warning sign it is with any other peptide.

4. 04

   Storage before and after mixing

   Unopened lyophilized vials keep cool and dark. Once reconstituted, the vial is refrigerated, with the same roughly 28 day convention that applies to punctured bacteriostatic water. Light protection gets more attention with GHK-Cu than with most peptides, so the reconstituted vial is commonly kept in a box or wrapped rather than sitting exposed on a shelf. Because a large vial can outlast the 28 day window by a wide margin at typical draw sizes, the discard date rather than the remaining volume is what determines the vial's life. Tracking the mix date in PepKit removes the guesswork on a vial that may still look nearly full when its window closes.

5. 05

   The syringe

   U-100 insulin syringes are standard for subcutaneous draws, where 100 units equal 1 mL and each unit is 0.01 mL. The larger water volumes GHK-Cu often calls for are measured with a regular syringe during mixing rather than an insulin syringe, since 10 mL is well beyond what an insulin syringe holds. The insulin syringe is for the draw, not the mix.

6. 06

   Common mistakes worth avoiding

   The recurring ones: assuming the blue color means something went wrong, choosing a water volume the vial cannot physically hold, treating a 50 mg vial like a 5 mg vial and ending up with draws too small to measure, leaving the reconstituted vial exposed to light, and letting a large vial run past its discard window because it still looks full.