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Dietary supplement

Premium Organic Japanese Knotweed Ingredients & Drug Interactions

by ZenMen

Premium Organic Japanese Knotweed label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Premium Organic Japanese Knotweed against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Premium Organic Japanese Knotweed is a dietary supplement by ZenMen with 1 active ingredient. Its ingredients are commonly taken for source of resveratrol, heart and circulation support, inflammation.Based on those ingredients, 826 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Japanese Knotweed extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Premium Organic Japanese Knotweed by ZenMen

Ask about any prescription or over-the-counter medication and we check it for interactions with Premium Organic Japanese Knotweed by ZenMen — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Premium Organic Japanese Knotweed by ZenMen

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 1 active ingredient.

This product contains one active ingredient: Japanese Knotweed extract (also called Hu Zhang). Japanese Knotweed is a plant used in traditional medicine; the extract concentrates its active compounds, including a polyphenol called resveratrol.

The liquid also contains two inactive ingredients — sunflower glycerin and cane alcohol — which serve as the base and preservative.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

We hold no graded evidence for this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: overall wellness and immune function.
  • We looked for evidence on: immune support, antioxidant support, anti-inflammatory support.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

The evidence supporting Japanese Knotweed extract for its traditional uses isn't well established yet. Our data shows insufficient reliable evidence to rate it for hepatitis, rheumatoid arthritis, wound healing, gout, osteoarthritis, and unstable angina.

That doesn't mean it doesn't work — it means controlled human studies haven't been done or published widely enough to draw firm conclusions. If you're considering it for a specific condition, talk with your pharmacist or doctor about what the current research really shows.

The evidence, ingredient by ingredient Hu Zhang

How safe is it?

Some data gaps
Safety Information · database check
Some gaps

Safety data exists for these ingredients, but with some important gaps.

Why this rating?
  • We hold adverse-effect (side-effect) data for 0 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Japanese Knotweed has been used in traditional medicine, but human safety data for supplements are limited. The plant contains emodin, a compound that may cause digestive upset in some people.

Importantly, the safety data advises against use during pregnancy and breastfeeding — there isn't enough information to know whether it's safe for your baby, so this is one to skip if you're pregnant or nursing.

Side effects, ingredient by ingredient Hu Zhang

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Hu Zhang.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 827 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking ZenMen's Japanese Knotweed, double-check if you're on blood thinners or antiplatelet drugs (like warfarin or aspirin) — the supplement may increase bleeding risk. Also flag any medications broken down by your liver's CYP1A2, CYP2C19, CYP3A4, or CYP2E1 enzymes, estrogen replacement therapy, or carbamazepine (Tegretol).

Use the medication checker on this page with your exact medications to be sure.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no assessable stated purpose. Moderate medication interactions have been identified, and some safety-information gaps remain.

If you take blood thinners, seizure medications, or drugs metabolized by your liver's cytochrome P450 enzymes, check with your pharmacist before starting this. The evidence for its health benefits isn't established in the data we have.

Pregnant or breastfeeding? Avoid it.

Otherwise, discuss whether it fits your situation with your pharmacist or doctor.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jun 20, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Premium Organic Japanese Knotweed, straight from the product label.

Brand ZenMen
Barcode (UPC) X003YPX26N
Net contents 1.2 Ounce(s); 30 mL
Market status On market
Date entered into DSLD Jun 20, 2024
DSLD ID 310003
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Organic, Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Premium Organic Japanese Knotweed by ZenMen, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 mL
Maximum serving Sizes:
1 mL
Servings per container
30
UPC/BARCODE
X003YPX26N
IngredientAmount% DV
Japanese Knotweed extract0 NP--

Other ingredients: Sunflower Glycerin, Cane Alcohol

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula

ZenMen Premium & Organic Japanese Knotweed: A pure supplement derived from Japanese knotweed, known for its antioxidants and anti-inflammatory properties. It may support overall wellness and immune function, potentially aiding in promoting health.

Precautions

Consult a healthcare professional before use.

Caution: Do not exceed recommended dose.

Pregnant or nursing mothers, children under the age of 18 and individuals with a known medical condition should consult with a physician before taking this or any supplement.

Pregnant or nursing mothers, children under the age of 18 and individuals with a known medical condition should consult with a physician before taking this or any supplement. Keep out of reach of children.

Do not use if safety seal is damaged or missing.

Allergen information: Contains tree nut ingredients.

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, adults take one (1) ml daily or as recommended by a healthcare professional. For best results, use continuously for 3 months.

Storage

Store in a cool, dry place.

Formulation

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, or sesame seed ingredients.

Tick wellness aid

USDA Organic

Gluten Free GMO Free

Vegan

GMP

Certified Organic by Montana Department of Agriculture.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

General Statements

Zen inspired wellness

Naturopathic doctor formulated

Scan Me Scan to view certificates

Seals/Symbols

Manufactured in USA Third Party Tested USDA Organic

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Premium Organic Japanese Knotweed by ZenMen label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Premium Organic Japanese Knotweed label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Premium Organic Japanese Knotweed by ZenMen

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 mL Dosage formLiquid Servings per container30 Amounts shown are per serving.

Japanese Knotweed extract

Interacts with
826 drugs
0 NP per serving

Hu Zhang (Japanese knotweed root) is a traditional Chinese herb that is one of the richest natural sources of resveratrol and emodin. Some lab and ear...

Japanese Knotweed extract monograph & interactions

Other (inactive) ingredients: Sunflower Glycerin, Cane Alcohol. These complete the product’s ingredient list but are not active constituents.

Interaction report

Premium Organic Japanese Knotweed by ZenMen Drug Interactions

Want to check YOUR meds against Premium Organic Japanese Knotweed?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
826Drugs
826 Moderate

Ingredients driving the most interactions

Japanese Knotweed extract 826

Individual Drug Interactions

The ingredients in Premium Organic Japanese Knotweed interact with 826 drugs. Click any drug to see the details.

1 of the 1 ingredient in Premium Organic Japanese Knotweed interact with drugs. Each result below shows which ingredient is responsible. Japanese Knotweed extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Premium Organic Japanese Knotweed with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Japanese Knotweed extract7 drug types · 826 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, hu zhang might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
Hu zhang contains the constituent resveratrol. Resveratrol seems to have antiplatelet effects.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, hu zhang might increase levels of drugs metabolized by CYP1A2.
Hu zhang contains the constituent resveratrol. In vitro research shows that resveratrol might inhibit the CYP1A2 enzyme. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, hu zhang might increase levels of drugs metabolized by CYP2C19.
Hu zhang contains the constituent resveratrol. In vitro research shows that resveratrol might inhibit the CYP2C19 enzyme. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, hu zhang might increase levels of drugs metabolized by CYP2E1.
Hu zhang contains the constituent resveratrol. In vitro research shows that resveratrol might inhibit the CYP2E1 enzyme. Also, a pharmacokinetic study shows that taking resveratrol 500 mg daily for 10 days prior to taking a single dose of chlorzoxazone 250 mg increases the maximum concentration of chlorzoxazone by about 54%, the area under the curve of chlorzoxazone by about 72%, and the half-life of chlorzoxazone by about 35%. Chlorzoxazone is used as a probe drug for CYP2E1.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, hu zhang might increase levels of drugs metabolized by CYP3A4.
Hu zhang contains the constituent resveratrol. In vitro research shows that resveratrol might inhibit the CYP3A4 enzyme. However, a clinical study in adults with NAFLD found that adding resveratrol 3000 mg daily for 8 weeks did not necessitate dose adjustments to any established medications metabolized by CYP3A4.

Likelihood Possible Evidence D
Estrogens

Theoretically, hu zhang might competitively inhibit the effects of estrogen replacement therapy.
In vitro research shows that hu zhang might have estrogenic activity.

Likelihood Possible Evidence D
Carbamazepine (Tegretol)

Theoretically, hu zhang might increase the effects and adverse effects of carbamazepine.
In animals, blood and tissue levels of carbamazepine were increased when given in combination with hu zhang. It is thought that increased levels of carbamazepine are due to cytochrome P450 3A4 (CYP3A4) inhibition. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Japanese Knotweed extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Premium Organic Japanese Knotweed, from the product label.

ZenMen

See all ZenMen products
Name
ZenMen
Street Address
18695 Pony Express Dr #1541
City
Parker
State
CO
ZipCode
80134
Web Address
ZenMenHealth.com
Pharmacist Counseling Corner

Premium Organic Japanese Knotweed by ZenMen: Common Questions

Does Premium Organic Japanese Knotweed by ZenMen interact with any medications?
Yes. Based on its ingredients, Premium Organic Japanese Knotweed has a known interaction with 826 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Premium Organic Japanese Knotweed contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What is Japanese Knotweed extract and why is it in this product?
Japanese Knotweed is a plant used in traditional medicine, and the extract concentrates its active compounds — particularly resveratrol. The product is marketed for traditional wellness, though controlled human studies haven't yet established clear benefits for specific conditions.
Can I take this while pregnant or breastfeeding?
No, the safety data advises against use during pregnancy and breastfeeding. There isn't enough information to know whether it's safe for your baby, so it's best avoided during these times.
What side effects might I experience?
The extract contains emodin, a compound that may cause digestive upset in some people. No other adverse effects are listed in our data, but remember that supplement side effects aren't always fully documented.
Does this product actually work for the conditions it claims to help with?
Our data shows insufficient reliable evidence to rate Japanese Knotweed for hepatitis, rheumatoid arthritis, wound healing, gout, osteoarthritis, or unstable angina. That means controlled human studies haven't established whether it works for these uses.
Why is there cane alcohol in a supplement?
Cane alcohol is an inactive ingredient used as a preservative in liquid supplements. It helps keep the product stable and prevents spoilage.
If I'm on multiple medications, how do I know if this is safe for me?
Use the medication checker on this page to search your exact prescriptions against this product's ingredients. Pay special attention if you're on blood thinners, seizure drugs, or medications your liver breaks down — those carry documented interaction concerns.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Premium Organic Japanese Knotweed is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Premium Organic Japanese Knotweed label
Go deeper

The Full Monographs Behind Premium Organic Japanese Knotweed’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Hu Zhang

Interacts with 826 drugs

Hu Zhang (Japanese knotweed root) is a traditional Chinese herb that is one of the richest natural sources of resveratrol and emodin. Some lab and early human research looks interesting for...

Read the full Hu Zhang monograph →
Sources

Sources & How We Checked

Premium Organic Japanese Knotweed's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 19 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Hu Zhang 19 references
  1. Pace-Asciak CR, Rounova O, Hahn SE, et al. Wines and grape juices as modulators of platelet aggregation in healthy human subjects. Clin Chim Acta 1996;246:163-82. PubMed
  2. Bertelli AA, Giovannini L, Bernini W, et al. Antiplatelet activity of cis-resveratrol. Drugs Exp Clin Res 1996;22:61-3.
  3. Pace-Asciak CR, Hahn S, Diamandis EP, et al. The red wine phenolics trans-resveratrol and quercetin block human platelet aggregation and eicosanoid synthesis: implications for protection against coronary heart disease. Clin Chim Acta 1995;235:207-19.
  4. Bertelli A, Bertelli AA, Gozzini A, Giovannini L. Plasma and tissue resveratrol concentrations and pharmacological activity. Drugs Exp Clin Res 1998;24:133-8.
  5. Bertelli AA, Giovannini L, Giannessi D, et al. Antiplatelet activity of synthetic and natural resveratrol in red wine. Int J Tissue React 1995;17:1-3.
  6. Piver B, Berthou F, Dreano Y, Lucas D. Inhibition of CYP3A, CYP1A and CYP2E1 activities by resveratrol and other non volatile red wine components. Toxicol Lett 2001;125:83-91. PubMed
  7. Matsuda H, Shimoda H, Morikawa T, Yoshikawa M. Phytoestrogens from the roots of Polygonum cuspidatum (Polygonaceae): structure-requirement of hydroxyanthraquinones for estrogenic activity. Bioorg Med Chem Lett 2001;11:1839-42. PubMed
  8. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol 2005;98:295-300. PubMed
  9. Chang, T. K., Chen, J., and Lee, W. B. Differential inhibition and inactivation of human CYP1 enzymes by trans-resveratrol: evidence for mechanism-based inactivation of CYP1A2. J.Pharmacol.Exp.Ther. 2001;299(3):874-882.
  10. Dobrydneva, Y., Williams, R. L., and Blackmore, P. F. trans-Resveratrol inhibits calcium influx in thrombin-stimulated human platelets. Br.J.Pharmacol. 1999;128(1):149-157.
  11. Kirk, R. I., Deitch, J. A., Wu, J. M., and Lerea, K. M. Resveratrol decreases early signaling events in washed platelets but has little effect on platalet in whole food. Blood Cells Mol.Dis. 2000;26(2):144-150.
  12. Zbikowska, H. M. and Olas, B. Antioxidants with carcinostatic activity (resveratrol, vitamin E and selenium) in modulation of blood platelet adhesion. J Physiol Pharmacol. 2000;51(3):513-520.
  13. Olas, B., Wachowicz, B., Saluk-Juszczak, J., and Zielinski, T. Effect of resveratrol, a natural polyphenolic compound, on platelet activation induced by endotoxin or thrombin. Thromb.Res 8-15-2002;107(3-4):141-145. PubMed
  14. Yu, C., Shin, Y. G., Kosmeder, J. W., Pezzuto, J. M., and van Breemen, R. B. Liquid chromatography/tandem mass spectrometric determination of inhibition of human cytochrome P450 isozymes by resveratrol and resveratrol-3-sulfate. Rapid Commun.Mass Spectro PubMed
  15. Ma, Z. H. and Ma, Q. Y. Resveratrol: a medical drug for acute pancreatitis. World J Gastroenterol. 6-7-2005;11(21):3171-3174. PubMed
  16. Pendurthi, U. R., Williams, J. T., and Rao, L. V. Resveratrol, a polyphenolic compound found in wine, inhibits tissue factor expression in vascular cells : A possible mechanism for the cardiovascular benefits associated with moderate consumption of wine. PubMed
  17. Chachay VS, Macdonald GA, Martin JH, Whitehead JP, O'Moore-Sullivan TM, Lee P, Franklin M, Klein K, Taylor PJ, Ferguson M, Coombes JS, Thomas GP, Cowin GJ, Kirkpatrick CM, Prins JB, Hickman IJ. Resveratrol does not benefit patients with nonalcoholic fatty
  18. Bedada SK, Neerati P. Resveratrol Pretreatment Affects CYP2E1 Activity of Chlorzoxazone in Healthy Human Volunteers. Phytother Res. 2016;30(3):463-8. PubMed
  19. Chi YC, Lin SP, Hou YC. A new herb-drug interaction of Polygonum cuspidatum, a resveratrol-rich nutraceutical, with carbamazepine in rats. Toxicol Appl Pharmacol 2012;263(3):315-22. PubMed

See these in context on the Hu Zhang monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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