I don't bother worrying about that anymore since Buhner said herbs can be taken with or without food:
It depends on the dosage, Buhner's highest dosage is really high for most herbs, so i think it matters less if u take them with food or without
However the german clinic that i get treatment from uses a modified list of Buhner herbs with much lower dosage, and they do say take them without food, the detox (chorella, etc..) and the therapy ones (andrographis, grapefruit seed, etc...), and with food the antioxidants (knotweed, turmeric, etc...).
I'd say if your stomach is up to it, try without food. If u have stomach issues, don't.