Drug & supplement interaction

Shiitake Mushroom + Granisetron

Granisetron brand names: Kytril, Sustol.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Shiitake Mushroom 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

Shiitake Mushroom 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 Shiitake Mushroom 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.

Shiitake Mushroom safety at a glance

Shiitake Mushroom overall Use caution Generally safe as a food, but concentrated supplements and raw mushrooms can cause reactions in some people.
Pregnancy Use caution Eating shiitake as food is likely fine, but concentrated supplements should be avoided due to lack of safety data.
Breastfeeding Use caution Food amounts are likely fine, but there is not enough data on supplement doses, so caution is advised.

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

Still wondering about combining Granisetron and Shiitake Mushroom? 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. Shiitake Mushroom has documented interactions with 2 drug classes — the most serious being cytochrome p450 2d6 (cyp2d6) substrates (moderate) and immunosuppressants (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

Shiitake Mushroom Does Interact With Other Medications

Shiitake Mushroom has 312 moderate known drug interactions in our database — Granisetron isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Shiitake Mushroom

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

What to actually watch for

No Interaction Found — But Data Suggests Shiitake Mushroom 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. 2 of them are worth acting on rather than waiting out — marked below.

  • Shortness of breath Worth acting on Additional detail

    Shiitake Mushroom

    “In mushroom workers, hypersensitivity pneumonitis due to shiitake spore inhalation has occurred. Symptoms include difficulty breathing, chest pain, a dry cough, asthma, and rhinitis.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in asthma.

    6 sources cited
    1. 1150. Murakami M, Kawabe K, Hosoi Y, et al. Decreased pulmonary perfusion in hypersensitivity pneumonitis caused by Shiitake mushroom spores. J Intern Med 1997;241:85-8. PubMed
    2. 1151. Matsui S, Nakazawa T, Umegae Y, Mori M. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Intern Med 1992;31:1204-6.
    3. 74776. Fujiwara, K., Sato, T., Yonei, T., Genba, K., Nogami, N., and Yamadori, I. [A case of chronic hypersensitivity pneumonitis induced by shiitake mushroom spores]. Nihon Kokyuki.Gakkai Zasshi 2000;38(12):908-913.
    4. 74813. Sastre, J., Ibanez, M. D., Lopez, M., and Lehrer, S. B. Respiratory and immunological reactions among Shiitake (Lentinus edodes) mushroom workers. Clin.Exp.Allergy 1990;20(1):13-19.
    5. 94239. Ampere A, Delhaes L, Soots J, Bart F, Wallaert B. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Med Mycol. 2012 Aug;50(6):654-7. PubMed
    6. 94241. Boels D, Landreau A, Bruneau C, et al. Shiitake dermatitis recorded by French Poison Control Centers - new case series with clinical observations. Clin Toxicol (Phila). 2014 Jul;52(6):625-8. PubMed

    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

    Shiitake Mushroom

    “Orally, shiitake mushrooms can cause shiitake dermatitis, a skin eruption that resembles whiplash marks, usually found on the trunk and limbs. This dermatitis is thought to be a toxic response to lentinan or other compounds found normally in uncooked or inadequately cooked shiitake mushroom. The rash can be made worse by scratching.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 1148. Hanada K, Hashimoto I. Flagellate mushroom (Shiitake) dermatitis and photosensitivity. Dermatol 1998;197:255-7. PubMed
    2. 1152. Nakamura T. Shiitake (Lentinus edodes) dermatitis. Contact Dermatitis 1992;27:65-70.
    3. 74782. Lippert, U., Martin, V., Schwertfeger, C., Junghans, V., Ellinghaus, B., and Fuchs, T. Shiitake dermatitis. Br.J Dermatol. 2003;148(1):178-179.
    4. 74806. Mak, R. K. and Wakelin, S. H. Shiitake dermatitis: the first case reported from a European country. Br J Dermatol 2006;154(4):800-801. PubMed
    5. 94236. Ade R, Sukut C, Wiser HJ, Shockman S, Buescher L. Shiitake dermatitis demonstrating Köebner phenomenon. Int J Dermatol. 2015;54(5):e179-81.
    6. 94237. Adler MJ, Larsen WG. Clinical variability of shiitake dermatitis. J Am Acad Dermatol. 2012 Oct;67(4):e140-1. PubMed

    Granisetron

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

  • Fever Additional detail

    Shiitake Mushroom

    Recorded for Shiitake Mushroom in the same Natural Medicines adverse-effect record shown under An allergic reaction above.

    Granisetron

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

  • Tiredness Additional detail

    Shiitake Mushroom

    “In patients experiencing shiitake dermatitis, other symptoms may include prickling in the hands. Malaise has also been reported following oral intake or contact.

    Orally, the shiitake mushroom extract AHCC has been reported to cause mild and transient headache.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in cluster headache.

    4 sources cited
    1. 94256. Nguyen AH, Gonzaga MI, Lim VM, Adler MJ, Mitkov MV, Cappel MA. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017 Jun;56(6):610-616. PubMed
    2. 1151. Matsui S, Nakazawa T, Umegae Y, Mori M. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Intern Med 1992;31:1204-6.
    3. 94240. Baran W, Batycka-Baran A, Maj J, Szepietowski JC. Shiitake dermatitis - now also in Poland. Acta Derm Venereol. 2015 Jan;95(1):102-3. PubMed
    4. 30365. Spierings, E. L., Fujii, H., Sun, B., and Walshe, T. A Phase I study of the safety of the nutritional supplement, active hexose correlated compound, AHCC, in healthy volunteers. J Nutr Sci Vitaminol.(Tokyo) 2007;53(6):536-539. PubMed

    Granisetron

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

  • Diarrhea Additional detail

    Shiitake Mushroom

    “Orally, shiitake mushroom is generally well tolerated when cooked and consumed as a food.

    Most Common Adverse Effects:

    Orally: Abdominal discomfort, bloating, diarrhea, nausea, and vomiting.

    Serious Adverse Effects (Rare):

    Orally: Consumption of raw shiitake mushroom can cause shiitake dermatitis, a skin eruption resembling whiplash marks which can be accompanied by systemic symptoms.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in dermatitis.

    Granisetron

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

  • Vomiting / Nausea Additional detail

    Shiitake Mushroom

    “Orally, shiitake mushrooms can cause abdominal discomfort, including bloating, nausea, pain, vomiting, and diarrhea. Gastrointestinal symptoms, such as diarrhea, problems swallowing, or mouth ulcers have been associated with shiitake dermatitis.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 1149. Levy AM, Kita H, Phillips SF, et al. Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms. J Allergy Clin Immunol 1998;101:613-20. PubMed
    2. 30365. Spierings, E. L., Fujii, H., Sun, B., and Walshe, T. A Phase I study of the safety of the nutritional supplement, active hexose correlated compound, AHCC, in healthy volunteers. J Nutr Sci Vitaminol.(Tokyo) 2007;53(6):536-539. PubMed
    3. 30375. Sumiyoshi, Y., Hashine, K., Kakehi, Y., Yoshimura, K., Satou, T., Kuruma, H., Namiki, S., and Shinohara, N. Dietary administration of mushroom mycelium extracts in patients with early stage prostate cancers managed expectantly: a phase II study. Jpn.J Cl PubMed
    4. 30419. Thaiudom, S., Piyaniran, W., and Chutaputthi, A. A study of the efficacy of Active Hexose Correlated Compound (AHCC) in the treatment of chronic Hepatitis C patients at Phramongkutklao Hospital. The Medical News (Thailand) 2010;325:13-16.
    5. 94241. Boels D, Landreau A, Bruneau C, et al. Shiitake dermatitis recorded by French Poison Control Centers - new case series with clinical observations. Clin Toxicol (Phila). 2014 Jul;52(6):625-8. PubMed
    6. 94256. Nguyen AH, Gonzaga MI, Lim VM, Adler MJ, Mitkov MV, Cappel MA. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017 Jun;56(6):610-616. PubMed

    Granisetron

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

  • Headache Additional detail

    Shiitake Mushroom

    Recorded for Shiitake Mushroom in the same Natural Medicines adverse-effect record shown under Tiredness above.

    Granisetron

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

Reported for Shiitake Mushroom but not commonly for Granisetron: sun sensitivity, stomach upset, mouth irritation or sores and a bowel blockage.

Effects for Granisetron come from the ADVERSE REACTIONS section of its FDA label; effects for Shiitake Mushroom 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.

How to take them

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

At least one FDA label for a product containing Granisetron says to take it on an empty stomach. Most supplements — Shiitake Mushroom 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 Shiitake Mushroom 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 Shiitake Mushroom 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. Shiitake Mushroom 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.

Shiitake Mushroom has been studied for:

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

    Shiitake Mushroom for cancer

    It is unclear if oral shiitake mushroom 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 Shiitake Mushroom 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 Shiitake Mushroom 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 Shiitake Mushroom as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,613 real supplement products containing Shiitake Mushroom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Shiitake Mushroom. Even though Shiitake Mushroom 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 Shiitake Mushroom 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 Shiitake Mushroom
Top 25%

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

29 days ago today
Medication Granisetron
Steady interest

#2,576 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 Shiitake Mushroom reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Shiitake Mushroom and Granisetron records this page draws on were last updated July 10, 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 Shiitake Mushroom

What is Shiitake Mushroom?

  • Immune support
  • General wellness and nutrition
  • Cholesterol and heart health
  • Adjunct in cancer care (lentinan, AHCC)
  • Antioxidant support

Shiitake is a popular edible mushroom that is nutritious and safe to eat as food for most people. Some of its extracts (like lentinan and AHCC) have been studied as immune support, mainly alongside cancer treatment, but evidence for most supplement uses is limited. Talk with your pharmacist or doctor before using concentrated shiitake supplements.

Lentinula edodes · Omphalotaceae · Fruiting body (mushroom cap and stem); mycelium extracts · Whole food (fresh or dried mushrooms), capsules, tablets, powders, liquid extracts, and standardized extracts such as lentinan and AHCC

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

Shiitake Mushroom: dosing

There is no official standardized dose for shiitake supplements, and products vary widely in strength and form. Some research used specialized extracts (like lentinan given by injection in a medical setting), which is very different from over-the-counter capsules.If you choose a shiitake supplement, follow the directions on the product label and do not exceed the recommended amount.

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

Read the full Shiitake Mushroom 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 & Shiitake Mushroom

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

0Major
312Moderate
0Minor
2,517No known interaction
Moderate

312 interactions

Showing 60 of 312 moderate interactions — see all 312 on the Shiitake Mushroom page.

No interaction 2,517 drugs checked — show the list
Evidence & sources

Shiitake Mushroom References

The 67 references that drive our Shiitake Mushroom 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. Hitosugi M, Kitamura O, Takatsu A, Yoshino Y. Autopsy case of duodenal obstruction from impacted mushroom. J Gastroenterol 1998;33:562-5. PubMed
  2. Hanada K, Hashimoto I. Flagellate mushroom (Shiitake) dermatitis and photosensitivity. Dermatol 1998;197:255-7. PubMed
  3. Levy AM, Kita H, Phillips SF, et al. Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms. J Allergy Clin Immunol 1998;101:613-20. PubMed
  4. Murakami M, Kawabe K, Hosoi Y, et al. Decreased pulmonary perfusion in hypersensitivity pneumonitis caused by Shiitake mushroom spores. J Intern Med 1997;241:85-8. PubMed
  5. Matsui S, Nakazawa T, Umegae Y, Mori M. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Intern Med 1992;31:1204-6.
  6. Nakamura T. Shiitake (Lentinus edodes) dermatitis. Contact Dermatitis 1992;27:65-70.
  7. Ueda A, Obama K, Aoyama K, et al. Allergic contact dermatitis in shiitake (Lentinus edodes (Berk) Sing) growers. Contact Dermatitis 1992;26:228-33.
  8. Burikhanov, R. B., Wakame, K., Igarashi, Y., Wang, S., and Matsuzaki, S. Suppressive effect of active hexose correlated compound (AHCC) on thymic apoptosis induced by dexamethasone in the rat. Endocr.Regul. 2000;34(4):181-188.
  9. Gao, Y., Zhang, D., Sun, B., Fujii, H., Kosuna, K., and Yin, Z. Active hexose correlated compound enhances tumor surveillance through regulating both innate and adaptive immune responses. Cancer Immunol.Immunother. 2006;55(10):1258-1266. PubMed
  10. Ritz, B. W., Nogusa, S., Ackerman, E. A., and Gardner, E. M. Supplementation with active hexose correlated compound increases the innate immune response of young mice to primary influenza infection. J Nutr. 2006;136(11):2868-2873. PubMed
  11. Aviles, H., O'Donnell, P., Sun, B., and Sonnenfeld, G. Active hexose correlated compound (AHCC) enhances resistance to infection in a mouse model of surgical wound infection. Surg.Infect.(Larchmt.) 2006;7(6):527-535. PubMed
  12. Spierings, E. L., Fujii, H., Sun, B., and Walshe, T. A Phase I study of the safety of the nutritional supplement, active hexose correlated compound, AHCC, in healthy volunteers. J Nutr Sci Vitaminol.(Tokyo) 2007;53(6):536-539. PubMed
  13. Aviles, H., O'Donnell, P., Orshal, J., Fujii, H., Sun, B., and Sonnenfeld, G. Active hexose correlated compound activates immune function to decrease bacterial load in a murine model of intramuscular infection. Am J Surg. 2008;195(4):537-545. PubMed
  14. Ritz, B. W. Supplementation with active hexose correlated compound increases survival following infectious challenge in mice. Nutr.Rev. 2008;66(9):526-531. PubMed
  15. Terakawa, N., Matsui, Y., Satoi, S., Yanagimoto, H., Takahashi, K., Yamamoto, T., Yamao, J., Takai, S., Kwon, A. H., and Kamiyama, Y. Immunological effect of active hexose correlated compound (AHCC) in healthy volunteers: a double-blind, placebo-controll

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 Shiitake Mushroom and Granisetron Together: Common Questions

Is it safe to take Shiitake Mushroom with Granisetron?
We do not list a known interaction between Shiitake Mushroom 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 Shiitake Mushroom and Granisetron have any of the same side effects?
Yes — our sources link each of them separately to 8 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 Shiitake Mushroom 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 Shiitake Mushroom 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 Shiitake Mushroom 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 Shiitake Mushroom in each. That is a conversation for your prescriber, especially if Granisetron is being adjusted to a target.
How was the Shiitake Mushroom and Granisetron combination checked?
Interactions in our licensed database are recorded against drug classes. Granisetron is filed under 3 classifications, and Shiitake Mushroom has documented interactions with 2 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 Shiitake Mushroom interact with any other medications?
Yes. Shiitake Mushroom has 312 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 — Shiitake Mushroom 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

Still Have a Question About Granisetron and Shiitake Mushroom?

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Ask a pharmacist

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.