When I first started looking into CS, several years ago, I did find a couple of instances of Colloidal Silver being used by IV method for specific cases, I think one happens to be here on CZ I seem to remember, it was some years ago though. I found one case where CS was injected directly into a cancer tumour also,(not here on CZ), but some searching would be required again to try and find the articles. God only knows what quantity, preparation etc etc would be required for it to be administered though, assuming you found a medical practitioner who would give you the time of day to discuss it. Injecting is not something I would consider unless I had done a lot of serious research into it, however, having said that, I personally don't discount it yet, pending results of considerable further research. I did find several articles, available in the public domain, regarding this method used on/in animal studies. I didn't stop to read them though as it was not my area of interest...sometime in the future maybe.