The same amount of GHK-Cu reaches the tissue
Yes, there are lots of websites that sell it in pill form, but when push comes to shove, McGuire notes, most people using it for improved running performance appear to be injecting it

Experts explain that extremolytes work to protect extremophiles (organisms that are naturally found in extreme conditions) from their surroundings by forming and stabilizing protective water layers around their macromolecules and cell structures.7 But researchers note that ectoine, specifically, possesses certain properties that help it to shield proteins, cell membranes, and human tissues from allergens, UV light, heat, and dryness.7 And since peptides are the building blocks of proteins, it stands to reason that ectoine may help protect them, too.21 Looking at GHK-Cu, study authors explain that it may be prone to decomposition by skin proteases due to its limited enzyme resistance properties, making copper easily exposed to the external environment.9 So, to summarize, it appears that adding ectoine to a formula containing GHK-Cu may promote better peptide stability and protect it from harsh skin environments that could break it down, which could suggest that the copper peptides in this Allies of Skin product have more of an opportunity to work

Alternatively, systemic abdominal injection allows the peptide to migrate to the carpal tunnel area