I think that 3 to 6 capsules is sufficient but I don't think there would be any diminished returns at higher dosing. Vitamin C, Elderberry/Sambucus, and Black Currant have all been used and studied at some pretty high dosages.Do you think there would really be any benefit though in going above what would already be considered an intensive dose? It looks like to me as though 3-6 capsules would be quite sufficient. I would think the law of diminished returns may come into play..