When using Berkey Biofilm Drops™ please use as directed. At the doses recommended they are equivalent to taking a vitamin supplement. Berkey Biofilm Drops™ are not harmful to the human body. They may in fact be beneficial to the human body, which needs copper for good health.
For more information on copper and good health, please read this article: http://copperalliance.org.uk/copper-and-society/health