However, GHK-Cu helps calm the skin, reduce redness, soothe irritation, and support sensitive skin
These would include those who are pregnant or actively breastfeeding, as well as those with specific medical disorders and allergies

Standard reconstituted solution timeline Once reconstituted with bacteriostatic water: Maximum shelf life: 28-30 days refrigerated Never freeze reconstituted solution (destroys peptide) Clock starts immediately upon mixing Must be refrigerated (2-8C) always No room temperature storage Why 28-30 day limit: Bacteriostatic water contains 0.9% benzyl alcohol Preservative prevents bacterial growth ~30 days Peptide degradation also factors Conservative safe window Standard for all reconstituted peptides Day-by-day degradation: Temperature absolutely critical: Must refrigerate 2-8C Never leave at room temp (even hours degrade) Don't freeze (ice crystals damage peptide structure) Back of fridge (most stable temperature) Not in door (temperature fluctuates) Why freezing reconstituted solution fails: Ice crystals form in solution Crystals physically damage peptide bonds Copper-peptide complex disrupted Thawing doesn't restore structure Completely ineffective after freeze-thaw Common mistake: Thinking "frozen = longer shelf life" TRUE for powder, FALSE for liquid Reconstituted = refrigerate only Critical distinction See how long reconstituted peptides last guide

The best sites have adequate subcutaneous fat and easy access
(PubMed) The same review warns that systemic administration (IV) may shift melanin production, altering skins natural photoprotection and potentially increasing the risk of UV-induced skin damage or cancer a risk especially relevant in sunny climates
Very low prices can mean poor-quality products or weak safety