Yes it is! I was so excited to see that my body was strong enough to handle that flu. Many people I knew were in bed with it for at least a week. It hit hard but left quickly for me. No doubt about it, the cats claw is a wonder herb. I've noticed improvements in other areas since I started taking it too. I don't use the silver all the time, only when I feel especially run down and only for 3 days or so at a time (one spray 3 times a day).