Unless the silver is made wrong it cannot hurt you in any reasonable dose. My Silver puppy makes 20 ppm Ionic silver. I have drank 4 0unces a day at times. I could drink a gallon a day and it wouldn't hurt me it would just be a waste.
We just pour a couple ounces in the cats water dish. The cat loves it and drinks way more than usual. The stuff in the stores often is inferior and has protien stabilizers which might be harmfull but I doubt it. With the silver puppy you'll save tons of money over the long run.