These side effects occurred more frequently at higher doses or when the strength of the dose was increased
doi: 10.1016/j.ejphar.2012.12.012 132 KimSJeongJJungH-SKimBKimYELimDSet al
GHK, GHK-Cu, and Free Copper: Research Differences Cell-Signaling Research GHK-Cu may be examined in cellular systems to evaluate changes in protein phosphorylation, transcriptional activity, enzyme expression, and secreted molecular markers
Larger jumps risk triggering intolerance that wouldn't occur with gradual progression
However, it is important to choose a product that is free of irritants and fragrances and has been tested for safety on sensitive skin
Right now, there are several that have been evaluated by the National Institute for Health and Care Excellence and can be used in the NHS while more evidence is being generated