Drug & supplement interaction

Kava + Granisetron

Granisetron brand names: Kytril, Sustol.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Kava and Granisetron 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 Granisetron states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Kava and Granisetron

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 Granisetron and Kava 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.

Kava safety at a glance

Kava overall Use caution Kava may help anxiety but has been linked to rare, serious liver injury and is banned or restricted in some countries.

Pregnancy Avoid Kava is not considered safe during pregnancy and should be avoided.

Breastfeeding Possibly Unsafe When used orally. There is concern that the toxic pyrone constituents of kava can pass into breast milk; avoid using. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Granisetron and Kava? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Granisetron

Interactions in our licensed database are recorded against drug classes, not just single drug names. Granisetron is filed under 3 classifications — serotonergic drugs, serotonergic drugs, oral drugs. Kava has documented interactions with 12 drug classes — the most serious being cns depressants (major), alcohol (ethanol) (moderate) and cytochrome p450 2c19 (cyp2c19) substrates (moderate) — and none of Granisetron’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

Kava Does Interact With Other Medications

Kava has 248 major, 577 moderate, 341 minor known drug interactions in our database — Granisetron isn’t one of them. If you take anything else, check it against the full list below.

Major 248 Moderate 577 Minor 341 No known interaction 1,664 (incl. Granisetron)

Taking anything else?

Check Another of Your Medications Against Kava

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

What to actually watch for

No Interaction Found — But Data Suggests Kava and Granisetron May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 3 of them are worth acting on rather than waiting out — marked below.

Raised blood pressure Worth acting on Additional detail
Kava
“Long-term use of very large amounts of kava, especially in high doses (400 mg kava pyrones daily), has been associated with overall poor health including symptoms of low body weight, reduced protein levels, puffy face, hematuria, increased red blood cell volume, decreased platelets and lymphocytes, and possibly pulmonary hypertension.”

Kava · Natural Medicines adverse-effect record, reported in hypertension.
1 source cited

6402. Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.
“Orally, kava may cause shortness of breath, possibly due to pulmonary hypertension.”

Kava · Natural Medicines adverse-effect record, reported in hypertension.
1 source cited

6402. Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.
Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
Shortness of breath Worth acting on Additional detail

Kava

Recorded for Kava in the same Natural Medicines adverse-effect record shown under Raised blood pressure above.

Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
An allergic reaction Worth acting on Additional detail
Kava
“Orally, kava can cause allergic skin reactions, including sebotropic eruptions, delayed-type hypersensitivity, or urticarial eruption. In one case of kava-associated urticarial eruption, biopsy revealed neutrophilic sebaceous glands with lymphocytic infiltrate. Chronic use of high doses of kava has also been associated with kava dermopathy, which consists of reddened eyes; dry, scaly, flaky skin;”

Kava · Natural Medicines adverse-effect record, reported in dermatitis.
6 sources cited

4032. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed

11370. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.

28489. Huynh JC, Asgari MM, Moore MM. Sebotropic eruption associated with use of oral kava kava supplement. Clin Exp Dermatol 2014;39(7):816-8. PubMed

57277. Grace, R. Kava-induced urticaria. J Am Acad Dermatol 2005;53(5):906. PubMed

57325. Jappe, U., Franke, I., Reinhold, D., and Gollnick, H. P. Sebotropic drug reaction resulting from kava-kava extract therapy: a new entity? J Am Acad Dermatol. 1998;38(1):104-106. PubMed

57343. Siegers CP, Honold E, Krall B, and et al. Results of the drug monitoring L 1090 with Laitan capsules. Arztl Forsch 1992;39:7-11.
Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
A fast or pounding heartbeat Additional detail

Kava

Recorded for Kava in the same Natural Medicines adverse-effect record shown under Raised blood pressure above.

Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
Drowsiness / Headache Additional detail
Kava
“Orally, kava may cause headache, dizziness, and drowsiness. It might also cause extrapyramidal side effects such as involuntary oral and lingual reflexes, twisting movements of the head and trunk, tremors, and other parkinsonian-like symptoms possibly due to dopamine antagonism.”

Kava · Natural Medicines adverse-effect record, reported in cluster headache.
6 sources cited

4032. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed

6402. Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.

11370. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.

11372. Pittler MH, Ernst E. Kava extract for treating anxiety. Cochrane Database Syst Rev 2003;(1):CD003383.

11373. Cairney S, Maruff P, Clough AR, et al. Saccade and cognitive impairment associated with kava intoxication. Hum Psychopharmacol 2003;18:525-33. PubMed

18316. Sarris J, Kavanagh DJ, Byrne G, et al. The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Psychopharmacology 2009;205:399-407. PubMed
Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
Anxiety or restlessness Additional detail
Kava
“Since the early 2000's, hepatotoxicity has been a particular concern with kava. Worldwide, there have been at least 100 reported cases of hepatotoxicity following use of kava products. However, some experts question the clinical validity of several of these cases.”

Kava · Natural Medicines adverse-effect record, reported in anxiety.
6 sources cited

7024. Escher M, Desmeules J, Giostra E, Mentha G. Hepatitis associated with Kava, a herbal remedy for anxiety. BMJ 2001;322:139.

7068. Russmann S, Lauterburg BH, Helbling A. Kava hepatotoxicity [letter]. Ann Intern Med 2001;135:68-9.

7086. Liver Toxicity With Kava. Pharmacist's Letter/Prescriber's Letter. January 2001.

7096. Consultation letter MLX 286: Proposals to prohibit the herbal ingredient Kava-Kava (Piper methysticum) in unlicensed medicines. Medicines Control Agency, United Kingdom, July 19, 2002.

11795. Gow PJ, Connelly NJ, Hill RL, et al. Fatal fulminant hepatic failure induced by a natural therapy containing kava. Med J Aust 2003;178:442-3. PubMed

17086. Li XZ, Ramzan I. Role of ethanol in kava hepatotoxicity. Phytother Res 2010;24:475-80. PubMed
Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
Tiredness Additional detail

Kava

Recorded for Kava in the same Natural Medicines adverse-effect record shown under Anxiety or restlessness above.

Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›
Nausea Additional detail
Kava
“Orally, kava may cause gastrointestinal upset, nausea, or dry mouth.”

Kava · Natural Medicines adverse-effect record, reported in dry mouth.
6 sources cited

2093. Pittler MH, Ernst E. Efficacy of kava extract for treating anxiety: systematic review and meta-analysis. J Clin Psychopharmacol 2000;20:84-9. PubMed

2094. Volz HP, Kieser M. Kava-kava extract WS 1490 versus placebo in anxiety disorders--a randomized placebo-controlled 25-week outpatient trial. Pharmacopsychiatry 1997;30:1-5. PubMed

4032. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed

11370. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.

18316. Sarris J, Kavanagh DJ, Byrne G, et al. The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Psychopharmacology 2009;205:399-407. PubMed

57228. Scherer, J. Kava-kava extract in anxiety disorders: an outpatient observational study. Adv.Ther. 1998;15(4):261-269.
Granisetron

Listed in the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed ›

Reported for Kava but not commonly for Granisetron: stomach upset, a low platelet count, memory problems and trouble passing urine.

Effects for Granisetron come from the ADVERSE REACTIONS section of its FDA label; effects for Kava come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Kava in Pregnancy & Breastfeeding

Lactation Possibly Unsafe

When used orally. There is concern that the toxic pyrone constituents of kava can pass into breast milk; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Granisetron Products Have a Food Rule — Kava Should Not Break It

At least one FDA label for a product containing Granisetron says to take it on an empty stomach. Most supplements — Kava included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Granisetron on its own and move Kava to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Granisetron 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.

Recommended Dosage ( 2.2 ): The recommended dosage in adults is 10 mg administered as a single subcutaneous injection at least 30 minutes before the start of emetogenic chemotherapy on Day 1.

From the Dosage and Administration section of the FDA label we read for Granisetron — 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.

Overlapping uses

What Granisetron Is Prescribed For, and What Kava Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Granisetron is a prescription medicine with approved uses on its FDA label. Kava is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Granisetron is prescribed for: Granisetron is used to prevent nausea and vomiting linked to emetogenic (nausea-causing) cancer chemotherapy — including high-dose cisplatin — and radiation therapy, including total body irradiation and fractionated abdominal radiation. Granisetron hydrochloride tablets and Granisol oral solution are approved for both the chemotherapy and radiation indications. Sancuso skin patch is approved for prevention of nausea and vomiting in adults receiving moderately and/or highly emetogenic chemotherapy regimens of up to 5 consecutive days. Granisetron hydrochloride injection (intravenous) is also used to prevent and treat postoperative nausea and vomiting in adults.

Read the rest of what Granisetron is prescribed for

Sustol (subcutaneous injection) is used in combination with other anti-nausea medicines in adults specifically for the prevention of acute and delayed nausea and vomiting associated with moderately emetogenic chemotherapy or anthracycline and cyclophosphamide combination chemotherapy regimens.

Kava has been studied for:

Cancer studied, not established Kava has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Kava for cancer

It is unclear if oral kava is beneficial in patients with cancer.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Granisetron on your own; if you are taking Kava for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Granisetron

This page covers Kava only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Granisetron page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 5-htp (moderate), Acetyl-l-carnitine (moderate) and Ayahuasca (moderate).

By severity: 2 major · 25 moderate · 11 minor.

From our pharmacist’s overview on the Granisetron page

“Granisetron (Kytril, Sustol) blocks serotonin signals to stop nausea from chemotherapy and surgery, and this is a list that warrants real caution before you add a supplement to it. Most of the entries raise serotonin themselves, and stacking them on a serotonin-acting drug can push toward serotonin syndrome, a dangerous overload of tha…”

Reviewed by 2 · Jul 18, 2026

Open the Granisetron interaction page

One more smart check

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

We hold 403 real supplement products containing Kava, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Kava. Even though Kava itself has no known interaction with Granisetron, 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 Kava and Granisetron 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 Kava

Top 25%

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

29 days ago today

Medication Granisetron

Steady interest

#2,457 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 Kava reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Kava and Granisetron records this page draws on were last updated July 11, 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Kava

What is Kava?

Anxiety and stress
Restlessness
Trouble sleeping
Relaxation in social or cultural settings
Menopausal symptoms

Kava is a Pacific Island plant traditionally used to promote relaxation and ease anxiety, and some studies suggest it may help mild anxiety. However, kava has been linked to rare but serious liver damage, so it should be used with caution, avoided by people with liver problems, and only used after talking with your pharmacist or doctor.

Piper methysticum · Piperaceae · Roots and rhizomes · Capsules, tablets, liquid extracts, tinctures, teas, and traditional water-based root drinks

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

Kava: dosing

There is no single established or standardized dose for kava, and products vary widely in how much kavalactone they contain. Because of this and the risk of liver harm, it is best not to guess at a dose on your own.If you and your healthcare provider decide kava is appropriate, follow the directions on the product label and use the lowest effective amount for the shortest time. Many experts advise limiting how long you use kava.

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

Read the full Kava monograph & all interactions

Medication

About Granisetron

What Is Granisetron Used For?

Brand names: Kytril, Sustol

Granisetron is used to prevent nausea and vomiting linked to emetogenic (nausea-causing) cancer chemotherapy — including high-dose cisplatin — and radiation therapy, including total body irradiation and fractionated abdominal radiation. Granisetron hydrochloride tablets and Granisol oral solution are approved for both the chemotherapy and radiation indications. Sancuso skin patch is approved for prevention of nausea and vomiting in adults receiving moderately and/or highly emetogenic chemotherapy regimens of up to 5 consecutive days.

Granisetron hydrochloride injection (intravenous) is also used to prevent and treat postoperative nausea and vomiting in adults. Sustol (subcutaneous injection) is used in combination with other anti-nausea medicines in adults specifically for the prevention of acute and delayed nausea and vomiting associated with moderately emetogenic chemotherapy or anthracycline and cyclophosphamide combination chemotherapy regimens.

See full Granisetron drug information

Keep checking

Other Drugs & Kava

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

248Major

577Moderate

341Minor

1,663No known interaction

248 Major 577 Moderate 341 Minor 1,663 No interaction

Major

248 interactions

Showing 60 of 248 major interactions — see all 248 on the Kava page.

Moderate

577 interactions

Showing 60 of 577 moderate interactions — see all 577 on the Kava page.

Minor

341 interactions

Showing 60 of 341 minor interactions — see all 341 on the Kava page.

No interaction 1,663 drugs checked — show the list

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

Showing the 60 most looked-up of 1,663 medications checked with no known interaction — see the full Kava list.

See the full Kava interactions page

See every supplement checked against Granisetron, ranked by severity

Evidence & sources

Kava References

The 71 references that drive our Kava 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.

Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
Strahl S, Ehret V, Dahm HH, Maier KP. [Necrotizing hepatitis after taking herbal medication]. Dtsch Med Wochenschr 1998;123:1410-4.
Spillane PK, et al. Neurological manifestations of kava intoxication. Med J Aust 1997;167:172-3. PubMed
Swensen JN. Man convicted of driving under the influence of kava. Salt Lake City, UT: Deseret News, 1996.
Pittler MH, Ernst E. Efficacy of kava extract for treating anxiety: systematic review and meta-analysis. J Clin Psychopharmacol 2000;20:84-9. PubMed
Volz HP, Kieser M. Kava-kava extract WS 1490 versus placebo in anxiety disorders--a randomized placebo-controlled 25-week outpatient trial. Pharmacopsychiatry 1997;30:1-5. PubMed
Heinze HJ, Munthe TF, Steitz J, Matzke M. Pharmacopsychological effects of oxazepam and kava-extract in a visual search paradigm assessed with event-related potentials. Pharmacopsychiatry 1994;27:224-30. PubMed
Munte TF, Heinze HJ, Matzke M, Steitz J. Effects of oxazepam and an extract of kava roots (Piper methysticum) on event-related potentials in a word recognition task. Neuropsychobiology 1993;27:46-53.
Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed
Schelosky L, Raffaup C, Jendroska K, Poewe W. Kava and dopamine antagonism. J Neurol Neurosurg Psychiatry 1995;58:639-40. PubMed
Norton SA, Ruze P. Kava dermopathy. J Am Acad Dermatol 1994;31:89-97.
Pizzorno JE, Murray MT, eds. Textbook of Natural Medicine. 2nd ed. Edinburgh:Churchill Livingstone, 1999.
Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.
Escher M, Desmeules J, Giostra E, Mentha G. Hepatitis associated with Kava, a herbal remedy for anxiety. BMJ 2001;322:139.
Russmann S, Lauterburg BH, Helbling A. Kava hepatotoxicity [letter]. Ann Intern Med 2001;135:68-9.
Liver Toxicity With Kava. Pharmacist's Letter/Prescriber's Letter. January 2001.
Consultation letter MLX 286: Proposals to prohibit the herbal ingredient Kava-Kava (Piper methysticum) in unlicensed medicines. Medicines Control Agency, United Kingdom, July 19, 2002.
Meseguer E, Taboada R, Sanchez V, et al. Life-threatening parkinsonism induced by kava-kava. Mov Disord 2002;17:195-6. PubMed
Ruze P. Kava-induced dermopathy: a niacin deficiency? Lancet 1990;335:1442-5. PubMed
Singh YN. Kava: an overview. J Ethnopharmacol 1992;37:13-45.
Bilia AR, Gallori S, Vincieri FF. Kava-kava and anxiety: growing knowledge about the efficacy and safety. Life Sci 2002;70:2581-97. PubMed
Wooltorton E. Herbal kava: reports of liver toxicity. CMAJ 2002;166:777.
Mathews JM, Etheridge AS, Black SR. Inhibition of human cytochrome P450 activities by kava extract and kavalactones. Drug Metab Dispos 2002;30:1153-7. PubMed
Logan JL, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjogren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol 2003;22:158-9.
Teschke R, Gaus W, Loew D. Kava extracts: safety and risks including rare hepatotoxicity. Phytomedicine 2003;10:440-6. PubMed
Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.
Schulze J, Raasch W, Siegers CP. Toxicity of kava pyrones, drug safety and precautions--a case study. Phytomedicine 2003;10:68-73.. PubMed
Pittler MH, Ernst E. Kava extract for treating anxiety. Cochrane Database Syst Rev 2003;(1):CD003383.
Cairney S, Maruff P, Clough AR, et al. Saccade and cognitive impairment associated with kava intoxication. Hum Psychopharmacol 2003;18:525-33. PubMed
Moulds RF, Malani J. Kava: herbal panacea or liver poison? Med J Aust 2003;178:451-3. PubMed
Gow PJ, Connelly NJ, Hill RL, et al. Fatal fulminant hepatic failure induced by a natural therapy containing kava. Med J Aust 2003;178:442-3. PubMed
Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
Weiss J, Sauer A, Frank A, Unger M. Extracts and kavalactones of Piper methysticum G. Forst (kava-kava) inhibit P-glycoprotein in vitro. Drug Metab Dispos 2005;33:1580-3. PubMed
Gurley BJ, Swain A, Barone GW, et al. Effect of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on digoxin pharmacokinetics in humans. Drug Metab Dispos 2007;35:240-5. PubMed
Gurley BJ, Swain A, Hubbard MA, et al. Clinical assessement of CYP2D6-mediated herb-drug interactions in humans: Effects of milk-thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea. Mol Nutr Food Res 2008;52:755-63.
Li XZ, Ramzan I. Role of ethanol in kava hepatotoxicity. Phytother Res 2010;24:475-80. PubMed
Bodkin R, Schneider S, Rekkerth D, et al. Rhabdomyolysis associated with kava ingestion. Am J Emerg Med 2012;30:635.el-3. PubMed
Donadio V, Bonsi P, Zele I, et al. Myoglobinuria after ingestion of extracts of guarana, Ginkgo biloba and kava. Ginkgo biloba and kava. Neurol Sci 2000;21:124. PubMed
Sarris J, Kavanagh DJ, Byrne G, et al. The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Psychopharmacology 2009;205:399-407. PubMed
Hannam S, Murray M, Romani L, Tuicakau M, J Whitfeld M. Kava dermopathy in Fiji: an acquired ichthyosis? Int J Dermatol 2014;53(12):1490-4. PubMed
Huynh JC, Asgari MM, Moore MM. Sebotropic eruption associated with use of oral kava kava supplement. Clin Exp Dermatol 2014;39(7):816-8. PubMed
Teschke R, Sarris J, Schweitzer I. Kava hepatotoxicity in traditional and modern use: the presumed Pacific kava paradox hypothesis revisited. Br J Clin Pharmacol 2012;73(2):170-4. PubMed
Scherer, J. Kava-kava extract in anxiety disorders: an outpatient observational study. Adv.Ther. 1998;15(4):261-269.
Humberston, C. L., Akhtar, J., and Krenzelok, E. P. Acute hepatitis induced by kava kava. J Toxicol.Clin Toxicol. 2003;41(2):109-113. PubMed
Schmidt, M. Are kavalactones the hepatotoxic principle of kava extracts? The pitfalls of the glutathione theory. J Altern Complement Med 2003;9(2):183-187. PubMed
Stickel, F., Baumuller, H. M., Seitz, K., Vasilakis, D., Seitz, G., Seitz, H. K., and Schuppan, D. Hepatitis induced by Kava (Piper methysticum rhizoma). J Hepatol. 2003;39(1):62-67. PubMed
Grace, R. Kava-induced urticaria. J Am Acad Dermatol 2005;53(5):906. PubMed
Christl, S. U., Seifert, A., and Seeler, D. Toxic hepatitis after consumption of traditional kava preparation. J.Travel.Med. 2009;16(1):55-56. PubMed
Teschke, R., Genthner, A., and Wolff, A. Kava hepatotoxicity: comparison of aqueous, ethanolic, acetonic kava extracts and kava-herbs mixtures. J.Ethnopharmacol. 6-25-2009;123(3):378-384. PubMed
Jappe, U., Franke, I., Reinhold, D., and Gollnick, H. P. Sebotropic drug reaction resulting from kava-kava extract therapy: a new entity? J Am Acad Dermatol. 1998;38(1):104-106. PubMed
Gessner B and Cnota P. Extract of the kava-kava rhizome in comparison with diazepam and placebo. Z Phytother 1994;15(1):30-37.
Johnson D, Frauendorf A, Stecker K, and et al. Neurophysiological active profile and tolerance of kava extract WS 1490, A pilot study with randomized evaluation. TW Neurolgie Psychiatrie 1991;5(6):349-354.
Keller F and Klohs M. A review of the chemistry and pharmacology of the constituents of Piper methysticum. Lloydia 1963;26:1-15.
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Kuchta K, Schmidt M, Nahrstedt A. German Kava Ban Lifted by Court: The Alleged Hepatotoxicity of Kava (Piper methysticum) as a Case of Ill-Defined Herbal Drug Identity, Lacking Quality Control, and Misguided Regulatory Politics. Planta Med. 2015;81(18):16 PubMed
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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 Kava and Granisetron Together: Common Questions

Is it safe to take Kava with Granisetron?

We do not list a known interaction between Kava and Granisetron. 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.

Do Kava and Granisetron have any of the same side effects?

Yes — our sources link each of them separately to 9 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

Should I take Kava and Granisetron at the same time of day?

At least one FDA label for a product containing Granisetron says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Granisetron on its own and move Kava to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.

Are Kava and Granisetron used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Kava in each. That is a conversation for your prescriber, especially if Granisetron is being adjusted to a target.

How was the Kava and Granisetron combination checked?

Interactions in our licensed database are recorded against drug classes. Granisetron is filed under 3 classifications, and Kava has documented interactions with 12 drug classes — none of Granisetron'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 Kava interact with any other medications?

Yes. Kava has 1,166 documented drug interactions in our database — Granisetron 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 Granisetron interact with any supplements?

Yes. Granisetron has documented interactions with 38 supplements in our database — Kava is not one of them. The Granisetron 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

Kava monograph Uses, safety profile, and every drug interaction in one place Granisetron drug information The full plain-English guide to this medication Granisetron supplement interactions Every supplement checked against Granisetron, 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 71 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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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.