I went directly to the Marley website, and it appears that they no longer use Melatonin in their product. I'm confused, as the previous information that I posted specifically states that Melatonin is one of their ingredients. If you go to their website, the list of ingredients on the can and directly on the home page, doesn't include Melatonin. Maybe they received the same FDA warning and removed the Melatonin from their product? I really don't know for sure.
The bottom line is that if Marley could remove it from their drinks and come out with a suitable substitute, than this is no big deal.