First of all, let me just say that I am a huge fan of CFAH supplements. However, the bottom line is that this brand of dietary supplement is not for everyone. This is because it contains Methylxanthines, which can be deadly to those with heart issues. In addition to that, as far as the possible side effects go, there aren't too many. In my CFAH CBD review I'm going to focus on the one danger that is listed on their website, but you should always talk to your doctor before taking anything.