Thoughts on GHKCU and increased cancer risk? Saw this for the first time this morning and lots of mixed opinions

I plan on starting my peptide journey next week with Reta. First timer. My plan was to start slow with .5.. my question is should I do .5 once a week starting out or twice a week? I hear some people saying .5 once a week is pointless. But definitely looking to avoid any yucky side effects