GHK-Cu: The Copper Tripeptide, from Structure to Vial Math

GHK-Cu is one of the smallest peptides in the catalog — three amino acids plus a copper ion. Researchers usually come to it for one of two reasons: the copper biochemistry, or the reconstitution math on a 50 mg vial. This guide covers both.

What the molecule is

GHK-Cu is the copper complex of glycine-histidine-lysine, a tripeptide first identified in human blood plasma. The full complex formula is C₁₄H₂₄N₆O₄Cu — and that copper atom is not decorative. The literature treats GHK and GHK-Cu as distinct subjects: the copper complex is the one referenced in fibroblast activity, collagen synthesis, and wound-repair pathway models.

The molecular weight works out to about 403.9 g/mol. It’s small, which matters when a protocol specifies molar concentrations — the calculator handles the formula directly.

Reconstituting the 50 mg vial

The 50 mg vial is the largest lyophilized peptide we carry, and that changes the numbers people expect:

• 50 mg = 50,000 µg
• With 2 mL bacteriostatic water: 25,000 µg/mL — each 0.1 mL holds 2,500 µg
• A 1,000 µg target dose = 40 µL = 4 units on a U-100 syringe
• With 5 mL water: 10,000 µg/mL, and the same 1,000 µg dose = 100 µL = 10 units

The reconstitution calculator has the GHK-Cu preset at 50 mg, so no mental math needed — but running it both ways is a good habit for double-checking lab work.

Regulatory status (2026)

GHK-Cu has the most turbulent file in the catalog: nominated, placed on the 503A Category 2 safety-risk list, and by April 2026 removed from both categorical lists — outside Category 1 and Category 2 while the FDA re-evaluates its compounding applications, with a February 2027 PCAC review on the calendar. Topical and injectable research contexts carry different regulatory weight. Track the queue in the 2026 regulatory timeline.

Practical handling

Lyophilized GHK-Cu stores at −20 °C; reconstituted solutions go in the refrigerator and follow the Certificate of Analysis window. The copper can tint a solution faintly blue at higher concentrations — a harmless physical property, not a sign of degradation, though it’s worth knowing so it doesn’t surprise a protocol log.

See GHK-Cu for purity (99.7%) and full specifications.

For laboratory research use only. Not medical advice.