Here's a U.S. government link stating it is safe but more studies need to be done, especially regarding long-term use of oral KB220z. The study focuses primarily on the intravenous use, and amazingly, states that one injection can lead to marked repair or increase in dopamine receptors. I'm not having any cravings for alcohol or opioids these days, but I do get bouts of what I call dullness. Not depression, just lack of energy, and the world loses its brightness, so to speak. I might look further into this. I've cut back on supplements for awhile, but maybe...