I have been using this product for many years. I was almost heartbroken when it was unavailable at the start of Covid. It’s back I’m I’ve stocked up on it. Since taking this, I almost never get the seasonal flu, and my previous sinus allergies are nearly nonexistent now. Only “issue” I’ve had is a bit of flatulence. Small price to pay for the efficacy. Please try it. Of course it’s not for everyone but I highly recommend it!