Whoops, sorry, I did miss it. I get mine off Amazon, but if you're not in the US, YMMV. Here it their web site FDA registered manufacturer of branded and private label dietary supplements based on nanotechnology and using FDA cGMPs I use copper because it seems a bit more effective than silver. Gold and platinum are all about like silver, IMHO MediCOPPER (True Colloidal Copper)-5 Gallons I like this brand because they're about the only one that gives the scientific basis for the colloidal particles, and they sell both ionic and non-ionic colloidal metals. Ionics use charged metallic ions, true colloidal use molecules in the single digit nanometer size. Among colloidal makers, there is a religious war over whether ionic non-ionic is best, with each saying the other type is bogus. In reality, the peer-reviewed papers I've seen say that ionic and non-ionic (true colloidal) are both effective. And I've seen no evidence, anecdotal or peer-reviewed that claims the colloidal harms any of the beneficial bacteria that might be in your gut. It exploits small openings in the cell walls of disease causing microbes, but leaves the good ones alone. There are plenty of other brands that are effective but nutraneering has a good web site, and the information I've seen agrees with the science I've seen. But be careful, the side effects can be brutal.