I recently purchased 454 gm (1 lb) of the rhizome of Polygonum cuspidatum, in bulk because it is high in resveratrol (read earlier post here)l and far cheaper than prepared Resveratrol capsules. As powder I get 454 gm for the same price that I would pay 72gm as capsules, 6 x cheaper.
This post is about PubMed Article on this supplement.
- “the paper summarized its pharmacological effects, including antibacterial, antiviral, anti-inflammatory, analgesic, cardiovascular system protection, liver protection, anti tumor, improving immunity pharmacology” 
- “and the mutual transformation between polydatin and resveratrol keeps balance; they both have the ability of antioxidative stress in vivo, and polydatin has a better effect than resveratrol, which hints that polydatin may be a substitute for resveratrol in antioxidant for clinical use.” 
- Polydatin supplementation ameliorates diet-induced development of insulin resistance and hepatic steatosis in rats 
- .In vitro and in vivo studies of the inhibitory effects of emodin isolated from Polygonum cuspidatumon Coxsakievirus B₄.
- Note: Coxsakievus are associated with many cases of CFS
- 8-Hydroxycalamenene isolated from the rhizomes of Reynoutria elliptica exerts neuroprotective effects both in vitro and in vivo .
- Polydatin alleviates non-alcoholic fatty liver disease in rats by inhibiting the expression of TNF-α and SREBP-1c .
This is available in bulk on Amazon.
NOTE: Chinese knotwood (Polygonum Multiflorum), and Japanese knotwood(Polygonum Cuspidatum) are DIFFERENT. I in-error assumed they were the same, see comment for comparisons between them.
Chinese knotweed supplements are recommended in doses between 8g and 25g per day, or as a tea, according to the Herbal Resource Guide. The Public Health Report notes that Japanese knotweed is the premier herb for Lyme’s disease. It’s suggested as a full-spectrum herb, meaning in its whole root form, in doses of 500mg to 2000mg three to four times per day for eight to 12 months. There may be benefits within two weeks to two months, according to the Public Health Report.
The Herbal Resource Guide notes that Chinese knotweed supplement can be sold in crude or unprocessed forms, as well as those forms that have undergone processing. The unprocessed forms exhibit more of the laxative qualities than the processed forms, and side effects of the supplement may be abdominal upset or loose stools. The Public Health Report says Japanese knotweed should not be used by pregnant women and may lead to a metallic taste in the mouth. The Oregon State University monograph on the concentrated knotweed supplement, resveratrol, notes that a single dose of up to 5g per day has not been found to cause any side effects. It is also not suggested for use in pregnant or lactating women, or in people with estrogen-sensitive cancers because of lack of evidence to prove safety. The herb may interact with several medications, such as blood thinners and drugs metabolized by the P-450 enzyme system in the liver.