The goal of this clinical trial is to investigate GHK and GHK-Cu blood levels pre- and post-intervention in healthy adults, and to investigate the efficacy of X39 patch on GHK and GHK-Cu blood levels in healthy adults compared to a placebo. The main questions it aims to answer are:
* What is the change in GHK and GHK-Cu levels from baseline to Day 8?
* What is the difference in the change in GHK and GHK-Cu levels from baseline to Day 8 between the X39 patch and placebo? Researchers will compare X39 patches to placebo patches to evaluate their effects on circulating blood levels of GHK and GHK-Cu in healthy adults.
Participants will be asked to complete a questionnaire and use the X39 patch or placebo patch.