Nutrition and supplement support
Protein and vitamin C
Skin repair requires adequate protein and nutrients. Include varied protein sources and fruit or vegetables containing vitamin C. Vitamin C participates in collagen formation; this normal role does not mean high-dose supplementation multiplies a copper peptide's effect.
If dietary intake is limited, address the reason and consider an appropriate supplement. A cosmetic goal should not lead to an unnecessarily restrictive diet that reduces the nutrients needed for skin and hair.
Copper and zinc
GHK-Cu does not create an automatic need for oral copper. Copper is found in foods such as nuts, seeds, whole grains and shellfish. Excess supplemental copper can be harmful, and a copper-metabolism disorder changes the discussion substantially.
Long-term high-dose zinc can reduce copper absorption and cause deficiency. Do not respond to that possibility by adding an arbitrary copper dose to a large zinc dose. Review total intake, the reason for supplementation and any relevant laboratory findings.
Hair-loss supplements
Iron, vitamin D or other supplementation may be appropriate when a deficiency contributes to shedding. They are not universal hair-growth treatments. Biotin is often promoted for hair, but unnecessary high doses can interfere with some laboratory tests, including important hormone and cardiac tests. Tell the laboratory and clinician about its use.
Collagen and sun protection
Oral collagen products have their own evidence and limitations. They do not replace adequate total protein, and their use does not establish synergy with GHK-Cu.
For photoageing goals, consistent sun protection is an essential part of the plan. Continuing heavy ultraviolet exposure while adding more products can undermine the very outcome being tracked. Skin-care routines should be tolerable enough to use consistently.