I started using Pro Colloidal Silver as a mouthwash for a tooth infection because it was the only thing that worked (short of the expense of a visit to the dentist. When I started with a cold, I dosed myself with it and the germs went away. I put it in the dog's drinking water too if they show signs of being under the weather. Pro Colloidal Silver is the only company that I've found that I just know are going to produce a consistently good quality product, delivery is quick and I always take advantage of their 2 for the price of one when buying 1 litre bottles. Happy to recommend.