Do we know for certain that grapefruit seed extract does not have systemic absorption, or is there just not enough research about that? Do you think that grapefruit seed extract really has toxic quarternary ammonium compounds? Best regards.
I go into this in some depth in the newest edition of Herbal Antibiotics (due out in June). From my research ALL GSE products do indeed seem to contain chemicals that I cannot in good conscience recommend people take. The plant itself IS antibacterial but the commercial products are, in my opinion, adulterated. There is going to be some systemic absorption but I haven’t spent enough time on it to find out just how much. Looking at grapefruit itself, without the additives, it just isn’t potent enough or systemic enough to make it through my filters. And yes, it is helpful for many people.