Hi. Sorry for late reply. I just saw your comment while updating it. Lithium orotate can provide a higher tissue concentration when used at the same dosage of lithium carbonate which requires prescription in many countries. Litetature indicates that orotate form is more biovailable, pass the brain blood barrieer hence is considered more effective. Please note that this is not help advice so I only provide this information based on my reviews for awareness. Thank you for your comment.