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Dietary supplement

Hu Zhang Ingredients & Drug Interactions

by Hawaii Pharm

Hu Zhang label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Hu Zhang 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

Hu Zhang is a dietary supplement by Hawaii Pharm 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 wildcrafted Hu Zhang 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 Hu Zhang by Hawaii Pharm

Ask about any prescription or over-the-counter medication and we check it for interactions with Hu Zhang by Hawaii Pharm — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Hu Zhang by Hawaii Pharm

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 Aug 6, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Hu Zhang by Hawaii Pharm contains one active ingredient: wildcrafted Hu Zhang extract, a traditional plant preparation. The extract comes suspended in a liquid base made from vegetable palm glycerin, pharmaceutical-grade alcohol, and artesian Hawaiian purified water.

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

This is a single-ingredient Hu Zhang product and its label doesn't state a use — see Hu Zhang's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence for Hu Zhang isn't established for the uses listed in our data. We hold insufficient reliable evidence to rate its effectiveness for hepatitis, rheumatoid arthritis, wound healing, gout, osteoarthritis, or unstable angina.

That doesn't mean it doesn't work — it means the clinical research we have isn't robust enough to say whether it does.

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.

Hu Zhang has limited safety data in humans. Its emodin content may cause digestive upset.

The safety information we hold advises against use in pregnancy and while breastfeeding because there isn't enough data to know it's safe, and some compounds in Hu Zhang may affect the uterus or bowel. We have no adverse effects listed from clinical trials, but the overall human safety profile remains incomplete.

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 you take Hu Zhang, double-check if you're on blood thinners or antiplatelet drugs (like warfarin or aspirin), since the product may increase your bleeding risk. Also check any medications metabolized by CYP1A2, CYP2C19, CYP3A4, or CYP2E1 liver enzymes — Hu Zhang may raise their levels.

If you take estrogen replacement therapy or carbamazepine, run those by your doctor or pharmacist too.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and some safety-information gaps remain.

Hu Zhang is a traditional remedy with unclear effectiveness for the conditions listed in our data and limited safety information in people. If you take blood thinners, antiplatelet drugs, certain liver-metabolized medications, estrogen therapy, or carbamazepine, you'll want to clear this with your doctor or pharmacist before starting.

The same goes if you're pregnant or breastfeeding — there isn't enough safety data, so talk it over with your healthcare provider.

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 Oct 23, 2020.

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 Hu Zhang, straight from the product label.

Brand Hawaii Pharm
Barcode (UPC) 0787699238241
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Oct 23, 2020
DSLD ID 237303
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Hu Zhang by Hawaii Pharm, 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:
0.7 mL
Maximum serving Sizes:
1 mL
Servings per container
120
UPC/BARCODE
0787699238241
IngredientAmount% DV
wildcrafted Hu Zhang extract970 mg--

Other ingredients: Vegetable Palm Glycerin, pharmaceutical grade Alcohol, artesian Hawaiian purified Water

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.
General Statements

Hawaii Pharm Herbal Extract Highest quality since 2008

Made with Aloha!

Formulation

Contains no GMO, gluten, artificial colors, heavy metals, preservatives, pesticides, fertilizers.

Super concentrated liquid herbal extract. Dry herb/menstruum ratio: 1:3.

Manufactured in an FDA registered facility.

Non GMO Gluten free

Made in USA, Hawaii

Suggested/Recommended/Usage/Directions

Directions for use: Shake well before using. Take about 20-30 drops (0.7-1 ml, one full squeeze of the dropper bulb) to 2-4 oz of juice or water up to 4 times per day.

Precautions

Warning: Keep out of the reach of children.

May have contraindications. We recommend to seek expert medical advice before taking.

Do not use if you are allergic to any ingredients.

Consult a physician before using during pregnancy, if nursing or taking any medications.

Do not use if seal is broken or missing.

Storage

Store in a cool dry place.

Formula

(Polygonum cuspidatum)

FDA Statement of Identity

Herbal Dietary Supplement

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.

Seals/Symbols

FDA Registered Facility Made in United States of America USA

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

See for yourself

Hu Zhang by Hawaii Pharm label

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

Hu Zhang 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 Hu Zhang by Hawaii Pharm

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

Serving size0.7 mL Dosage formLiquid Servings per container120 Amounts shown are per serving.

Wildcrafted Hu Zhang extract

Interacts with
826 drugs
970 mg 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...

Wildcrafted Hu Zhang extract monograph & interactions

Other (inactive) ingredients: Vegetable Palm Glycerin, Pharmaceutical grade Alcohol, Artesian Hawaiian purified Water. These complete the product’s ingredient list but are not active constituents.

Interaction report

Hu Zhang by Hawaii Pharm Drug Interactions

Want to check YOUR meds against Hu Zhang?

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

wildcrafted Hu Zhang extract 826

Individual Drug Interactions

The ingredients in Hu Zhang interact with 826 drugs. Click any drug to see the details.

1 of the 1 ingredient in Hu Zhang interact with drugs. Each result below shows which ingredient is responsible. wildcrafted Hu Zhang extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Hu Zhang 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.

wildcrafted Hu Zhang 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
wildcrafted Hu Zhang extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Hu Zhang, from the product label.

Hawaii Pharm

See all Hawaii Pharm products
Name
Hawaii Pharm LLC
City
Honolulu
State
HI
ZipCode
96815
Web Address
www.hawaiipharm.com
Pharmacist Counseling Corner

Hu Zhang by Hawaii Pharm: Common Questions

Does Hu Zhang by Hawaii Pharm interact with any medications?
Yes. Based on its ingredients, Hu Zhang 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?
Hu Zhang 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.
Is Hu Zhang safe to use while I'm pregnant?
There isn't enough safety data to know either way, and some compounds in Hu Zhang may affect the uterus. Talk with your doctor or pharmacist before taking it if you're pregnant or planning to become pregnant.
Can I breastfeed while taking Hu Zhang?
The safety data advises against it. There isn't enough information to know it's safe while breastfeeding, so check with your doctor or pharmacist for personalized advice.
What does Hu Zhang do?
Hu Zhang is traditionally used for several conditions — hepatitis, rheumatoid arthritis, wound healing, gout, osteoarthritis, and unstable angina — but we don't have enough reliable clinical evidence to confirm it works for any of them.
What side effects does Hu Zhang cause?
We have no adverse effects reported from clinical trials. However, the emodin in Hu Zhang may cause digestive upset, and overall human safety data are limited, so some people may experience other effects we haven't documented.
Why does this product interact with so many medications?
Hu Zhang contains resveratrol, which can slow down several liver enzymes (parts of your cytochrome P450 system) that break down medications. When those enzymes are inhibited, drugs don't leave your body as quickly and can build up to higher levels, potentially causing stronger effects or side effects.

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

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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.

Hu Zhang label
Go deeper

The Full Monographs Behind Hu Zhang’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

Hu Zhang'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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