My son and I have been taking zinc picolinate for a few years now. A biochemist put my son on it for his copper overload, along with a lot of other supplements. I could tell a huge difference after a few weeks, and a few years later, his copper overload was gone. He no longer has vocal and motor tics, either. His ADHD is better than before. Just make sure to take it at night so you don't have nightmares! It sounds counterintuitive, but it's true.