I have taken knotweed daily for 4 years now. I have no plans to stop. I use the powdered herb, which is a lot cheaper than tinctures.
yep, not to contradict you WBF - as this is true - but if you are able to make your own tinctures the equation goes the other way
i mention it because i recently went the other way and changed from powder - which i had taken for around 4years also - to tincture because at the same equivalent dose - 30g a day - it worked out i would save around £30 a month by switching to tincture( and that includes paying for the alcohol).
interestingly, the dose of the tincture equates to less dry herb - presumably because tincturing pre-extracts the useful stuff in the herb - so Buhner advises 30g dry powder - vs 30ml 1:5 tincture - which requires only 6-7g of dry powder.