Absorption differences: injection vs topical Subcutaneous injection absorption: Rapid absorption into bloodstream Peak plasma concentration: 15-30 minutes 80-90% bioavailability Reaches target tissues quickly Systemic distribution Topical application absorption: Slower penetration through skin barrier Peak tissue concentration: 1-3 hours 5-15% bioavailability (most doesn't penetrate) Primarily local effects (skin where applied) Minimal systemic exposure Absorption comparison table: Why injection more effective: Direct systemic delivery Reaches all tissues Predictable dosing Lower total dose needed Better for body-wide effects When topical makes sense: Face/neck cosmetic use only Avoiding injections Already using skincare routine Combining both approaches (injection + topical) See our GHK-Cu 50mg copper peptide dosage guide for injection protocols

And many grey market peptide consumers, particularly those who source their peptides directly from compounding pharmacies overseas, dont believe the approval of these peptides will do much of anything to stem the grey market, especially because peptides purchased from overseas labs, often in China, are astronomically cheaper
Hyman M
In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds
When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating
Food Chem Toxicol 119:3749 Gupta P, Pruthi V, Poluri KM (2021) Mechanistic insights into Candida biofilm eradication potential of eucalyptol