Hi Sandi. I just started taking the NCD zeoloites this past week, and so far do not seem to be having any major herxheimer reaction. As a matter of fact, I am feeling more energy and less brain fog. I am slowly working my way up to 10 drops 3x per day. I think for cancer they may recommend getting up to a higher dose - maybe 15 drops 3 or 4x per day - I'm not sure.

Be well-

Andrea