 This stuff is amazing, and it has clinical research and data. This is scientific stuff. It works. I've interviewed one of the world's most authorities on these kinds of things, Dr. Madeline Munchugalo from Israel, who studied this bush her entire adult life, and she figured out how to make sure these viruses don't like it. Black elderberry extract. Zinc is another one. Zinc is something that interferes with the reproduction of viruses.