Drug & supplement interaction

Hu Zhang + Cobicistat

Cobicistat brand name: Tybost.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Hu Zhang and Cobicistat in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Cobicistat states a food rule worth keeping to.

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Interaction report

Hu Zhang and Cobicistat

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Cobicistat and Hu Zhang in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Hu Zhang safety at a glance

Hu Zhang overall Use caution Generally used in traditional medicine, but human safety data for supplements are limited and its emodin content may cause digestive upset.
Pregnancy Avoid Not enough safety data and some compounds may affect the uterus or bowel, so it is best avoided.
Breastfeeding Avoid There is not enough safety information, so avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cobicistat and Hu Zhang? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Cobicistat

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cobicistat is filed under 2 classifications — cytochrome p450 3a4 (cyp3a4) inhibitors, oral drugs. Hu Zhang has documented interactions with 7 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), cytochrome p450 1a2 (cyp1a2) substrates (moderate) and cytochrome p450 2c19 (cyp2c19) substrates (moderate) — and none of Cobicistat’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Hu Zhang Does Interact With Other Medications

Hu Zhang has 826 moderate known drug interactions in our database — Cobicistat isn’t one of them. If you take anything else, check it against the full list below.

Moderate 826 No known interaction 2,004 (incl. Cobicistat)
Taking anything else?

Check Another of Your Medications Against Hu Zhang

Covers the 2,830 medications we’ve checked against Hu Zhang. Pick one to open its full report.

What to actually watch for

What Cobicistat’s Own FDA Label Lists

This is not an interaction — none of it involves Hu Zhang. These are the most notable effects listed in the ADVERSE REACTIONS section of Cobicistat’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 7 of them are worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on mentioned in 44.9% of FDA reports for Cobicistat
  • Kidney stones Worth acting on
  • Severe muscle breakdown Worth acting on
  • Yellowing of the skin or eyes Worth acting on
  • Low mood Worth acting on
  • Hives Worth acting on
  • An allergic reaction Worth acting on
  • Vivid dreams or nightmares
  • Trouble sleeping
  • Itching

Showing the 10 most notable of 17 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Cobicistat. Read the label on DailyMed › Where a percentage is shown, it is the share of 20,779 voluntary FDA FAERS reports for Cobicistat that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Hu Zhang’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Hu Zhang side to compare — that is a limit of the record, not a statement that Hu Zhang has no side effects.

How to take them

Some Cobicistat Products Have a Food Rule — Hu Zhang Should Not Break It

At least one FDA label for a product containing Cobicistat says to take it with food. If you take Hu Zhang on an empty stomach out of habit, keep them separate — and take Cobicistat with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Cobicistat products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION TYBOST must be coadministered with atazanavir or darunavir at the same time, with food, and in combination with other HIV-1 antiretroviral agents.

From the Dosage and Administration section of the FDA label we read for Cobicistat — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Cobicistat

This page covers Hu Zhang only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cobicistat page lists 30 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), Cannabidiol (cbd) (moderate), Cannabinol (cbn) (moderate) and Cannabis (moderate).

By severity: 1 major · 19 moderate · 10 minor.

From our pharmacist’s overview on the Cobicistat page

“Activated charcoal is the one entry to understand first if you take cobicistat (Tybost). Charcoal soaks up drugs in the gut, and since cobicistat's entire job is boosting an HIV medicine to protective levels, blunting its absorption can put the whole regimen at risk.”

Reviewed by 2 · Jul 18, 2026

Open the Cobicistat interaction page

One more smart check

Taking Hu Zhang as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,014 real supplement products containing Hu Zhang, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hu Zhang. Even though Hu Zhang itself has no known interaction with Cobicistat, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Hu Zhang and Cobicistat Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Hu Zhang
Top 25%

#231 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Cobicistat
Top half

#1,199 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Hu Zhang reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Hu Zhang and Cobicistat records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Hu Zhang

What is Hu Zhang?

  • Source of resveratrol
  • Heart and circulation support
  • Inflammation
  • Liver and digestive complaints (traditional)
  • Cough and respiratory symptoms (traditional)
  • Skin and joint conditions (traditional topical use)

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 inflammation and heart health, but high-quality evidence in people is limited. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Reynoutria japonica · Polygonaceae · Root and rhizome · Capsules, tablets, powder, tincture, dried root for tea (decoction), standardized resveratrol extracts

An interaction check asks whether these two react with each other — it does not ask whether Hu Zhang is a good idea for someone in your situation. Here is what our Hu Zhang record says about it on its own.

Hu Zhang: dosing

There is no well-established standard dose of Hu Zhang. Products vary widely in strength, and some are standardized to a certain percentage of resveratrol while others are not.Because doses differ so much between products, the safest approach is to follow the directions on the label of the specific product you have.

From our Hu Zhang monograph — the full record covers uses, side effects and every documented interaction.

Read the full Hu Zhang monograph & all interactions
Medication

About Cobicistat

What Is Cobicistat Used For?

Brand name: Tybost

Tybost (cobicistat) is not itself an HIV treatment — it works by slowing the breakdown of certain HIV medicines so they stay active in your body long enough to work. Specifically, Tybost is used to boost the HIV medicines atazanavir or darunavir (once-daily dosing) as part of a complete HIV-1 treatment regimen in adults and in children weighing at least 14 kg (about 31 lbs).

Tybost is not interchangeable with ritonavir (another booster) for all HIV medicines. It is not recommended with darunavir twice-daily, fosamprenavir, saquinavir, or tipranavir.

Most-Reported Side Effects for Cobicistat

From FAERS, the FDA’s public side-effect reporting system (20,779 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Bone density decreased 8,112 reports
Chronic kidney disease 4,754 reports
Renal injury 4,577 reports
Tooth loss 4,186 reports
Bone loss 4,107 reports
See full Cobicistat drug information
Keep checking

Other Drugs & Hu Zhang

Browse every other medication we’ve checked against Hu Zhang — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
826Moderate
0Minor
2,003No known interaction
826 Moderate 2,003 No interaction
Moderate

826 interactions

Showing 60 of 826 moderate interactions — see all 826 on the Hu Zhang page.

No interaction 2,003 drugs checked — show the list

We also checked Hu Zhang against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,003 medications checked with no known interaction — see the full Hu Zhang list.

See the full Hu Zhang interactions page
See every supplement checked against Cobicistat, ranked by severity
Evidence & sources

Hu Zhang References

The 19 references that drive our Hu Zhang monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Hu Zhang and Cobicistat Together: Common Questions

Is it safe to take Hu Zhang with Cobicistat?
We do not list a known interaction between Hu Zhang and Cobicistat. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take Hu Zhang and Cobicistat at the same time of day?
At least one FDA label for a product containing Cobicistat says to take it with food. If you take Hu Zhang on an empty stomach out of habit, keep them separate and take Cobicistat with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Cobicistat products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Hu Zhang and Cobicistat combination checked?
Interactions in our licensed database are recorded against drug classes. Cobicistat is filed under 2 classifications, and Hu Zhang has documented interactions with 7 drug classes — none of Cobicistat's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Hu Zhang interact with any other medications?
Yes. Hu Zhang has 826 documented drug interactions in our database — Cobicistat is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Cobicistat interact with any supplements?
Yes. Cobicistat has documented interactions with 30 supplements in our database — Hu Zhang is not one of them. The Cobicistat interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Hu Zhang monograph Uses, safety profile, and every drug interaction in one place Cobicistat drug information The full plain-English guide to this medication Cobicistat supplement interactions Every supplement checked against Cobicistat, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 19 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Cobicistat and Hu Zhang?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.