I've been using it for over 10 years on and off with no issues. I do now take maybe 8 ounces to 16 ounces a day that I make with my Silvergen, and I take selenium and vitamin E daily - maybe for the last 8 months. I love silver because it's got no side effects for me, and has kept me over and over from needing Antibiotics (which is full of severe side effects). I love my Silvergen because the silver is clear (small particles not clumping) and strong. The silvergen folks say that this silver should not cause the argyria problem. I realize there is some small risk, but after some research I decided it was less of a risk for me to use the silver than the Antibiotics .