It is almost impossible to overdose on colloidal/ionic silver. I have many times taken over 10 ounces a days for multiple days and have never been the slightest tinge of blue. Now, I do not take it all the time - only when I think it is needed. But when I do take it, I take a LOT. Fact: millions of people around the world take colloidal/ionic silver - yet it is hard to find more than a handful of people who have argyria - and almost every one you do find took large amounts of improperly made silver or silver nitrate.