Polygonum cuspidatum - Japanese Knotweed

Polygonum Cuspidatum, more commonly known as Japanese knotweed, has been used for thousands of years in Traditional Chinese Medicine. Used so extensively in China, its dried root is officially listed in the Pharmacopoeia of the People’s Republic of China. Native to China, Japan and Korea, it is thought to not have made it to the United States until the late 1800’s. Having an incredibly strong root system combined with rapid growth and flowering, it has now spread through most of the states and is listed in the IUCN’s top 100 invasive species list.

Japanese knotweed began making its mark in the scientific community in 1963 when Michio Takaoka first isolated the compound Resveratrol from the roots. Fast forward to 1992 when the presence of Resveratrol was concluded to be responsible for the cardioprotective effect of wine (Baur and Sinclair, 2006). Now we are getting somewhere! Resveratrol appears in many plants at varying amounts; however, red wine grapes and Japanese knotweed are believed to have the highest concentrations. The role of Resveratrol in a plant is believed to be one of protection against microbial infection, UV radiation, and is thought of as a broad plant defense system. While known primarily for its Resveratrol content, Japanese knotweed has been found to have many other chemical compounds, such as emodin, polydatin, quercetin and catechin, that prove to be very promising in the treatment of many health issues that we see today.

My personal experience with Japanese knotweed started when I was diagnosed with chronic Lyme disease. I had heard of its use in the area before, but had no real reason to explore it. Well, now I did. If you are into alternative medicine at all and think of Lyme disease, Stephen Buhner comes up in every search. His claims on the herb are very detailed: "A broadly systemic plant, Japanese knotweed enhances and modulates immune function, is active against a number of gram-negative and gram-positive bacteria including leptospira and Treponema denticola spirochetes, is anti-inflammatory for both bacterial and arthritic inflammations, protects the body against endotoxin damage, helps reduce Herxheimer reactions, and is a cardio-protector.

Polygonum cuspidatum's constituents cross the blood-brain barrier where they exert actions on the central nervous system: anti-microbial, anti-inflammatory, as protectants against oxidative and microbial damage, and as calming agents. The herb specifically protects the brain from inflammatory damage, microbial endotoxins, and bacterial infections.

Knotweed enhances blood flow, especially to the eye, heart, skin, and joints. This makes it especially useful in Lyme as it facilitates blood flow to the areas that are difficult to reach to kill the spirochetes. It is a drug and herb synergist, facilitating the movement of other herbs and drugs into these hard-to-reach places when taken with them."

As of this post, I have more than a dozen research papers, articles and excerpts spread around the table in front of me, touting the incredible potential of this herb. What I believe is most important to share with you is this: I have been using Japanese knotweed since I was diagnosed with chronic Lyme disease because I believe in it, and I continue using it because I am better. I have tried numerous herbs in various forms that have come and gone, but I have never left this one out of my daily regimen.

Now, after spending so much time digging through research on polygonum cuspidatum, I consider it part of my “every day” routine for much more than Lyme. In addition to Buhner’s claims, there are reported positive effects on intestinal flora, spleen protection, antitumor, anticancer and antiviral activities.

I will even go so far as to say this: maybe the spread of Japanese knotweed throughout the U.S. is nature’s way of throwing us a bone in what would become a serious health issue – Lyme disease.

As with any herbal preparation, consider what you are taking already for any contraindications, and consult your doctor.




Buhner,S.H. (2005) Healing Lyme. Silver City, NM: Raven Press.

Wu X, Li Q, Feng Y, Ji Q. Antitumor Research of the Active Ingredients from Traditional Chinese Medical Plant Polygonum Cuspidatum. Evid Based Complement Alternat Med. 2018;2018:2313021. Published 2018 Nov 21. doi:10.1155/2018/2313021

Espinoza JL, Trung LQ, Inaoka PT, et al. The Repeated Administration of Resveratrol Has Measurable Effects on Circulating T-Cell Subsets in Humans. Oxid Med Cell Longev. 2017;2017:6781872. doi:10.1155/2017/6781872

Chenyang Guo et al 2018 IOP Conf. Ser.: Mater. Sci. Eng. 301 012062

Zhang H, Li C, Kwok ST, Zhang QW, Chan SW. A Review of the Pharmacological Effects of the Dried Root of Polygonum cuspidatum (Hu Zhang) and Its Constituents. Evid Based Complement Alternat Med. 2013;2013:208349. doi: 10.1155/2013/208349. Epub 2013 Sep 30