I had die-off right away, when I started using xylitol, the first day when I used only a teaspoon. I haven't had a lot of allergies, so I'm not sure if xylitol will take care of all of them, but I do know a lady who has been using Xlear, a nasal spray and she says it has really been helping. She is looking for the type I used. I hope this helps. Feel better!