Drug & supplement interaction

Shiitake Mushroom + Tofacitinib

Tofacitinib brand names: Xeljanz, Xeljanz XR.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Shiitake Mushroom has a moderate interaction with Tofacitinib. Theoretically, taking shiitake mushroom might decrease the effects of immunosuppressive therapy.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Shiitake Mushroom and Tofacitinib

Here is the interaction we found between these two, with the evidence behind it.

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Tofacitinib

Tofacitinib falls under IMMUNOSUPPRESSANTS — the group Shiitake Mushroom interacts with.

Theoretically, taking shiitake mushroom might decrease the effects of immunosuppressive therapy.
In vitro evidence suggests that shiitake mushroom extracts stimulate immune function.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thinking behind this one. Tofacitinib (Xeljanz) works by calming down an overactive immune system, which is exactly why it helps with rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. Shiitake mushroom, especially in concentrated extract form, contains compounds like lentinan that may stimulate immune activity. So in theory these two pull in opposite directions, and a shiitake supplement could blunt how well your tofacitinib controls things, meaning more joint pain, swelling, or flare-ups.

I want to be honest though: this concern is theoretical, based on lab studies, not real patient cases. Eating shiitake as food in a meal is very unlikely to cause problems. The bigger question is concentrated supplements. Before adding one, please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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.
  2. 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
  3. 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
  4. 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
  5. 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
  6. Ritz, B. W. Supplementation with active hexose correlated compound increases survival following infectious challenge in mice. Nutr.Rev. 2008;66(9):526-531. PubMed
  7. 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
  8. Wang, S., Welte, T., Fang, H., Chang, G. J., Born, W. K., O'Brien, R. L., Sun, B., Fujii, H., Kosuna, K., and Wang, T. Oral administration of active hexose correlated compound enhances host resistance to West Nile encephalitis in mice. J Nutr. 2009;139(3 PubMed
  9. Yin, Z., Fujii, H., and Walshe, T. Effects of active hexose correlated compound on frequency of CD4+ and CD8+ T cells producing interferon-gamma and/or tumor necrosis factor-alpha in healthy adults. Hum.Immunol. 2010;71(12):1187-1190.
  10. Lee, W. W., Lee, N., Fujii, H., and Kang, I. Active Hexose Correlated Compound promotes T helper (Th) 17 and 1 cell responses via inducing IL-1beta production from monocytes in humans. Cell Immunol. 2012;275(1-2):19-23.
  11. Daddaoua, A., Martinez-Plata, E., Ortega-Gonzalez, M., Ocon, B., Aranda, C. J., Zarzuelo, A., Suarez, M. D., de Medina, F. S., and Martinez-Augustin, O. The nutritional supplement Active Hexose Correlated Compound (AHCC) has direct immunomodulatory actio
  12. Roman, B. E., Beli, E., Duriancik, D. M., and Gardner, E. M. Short-term supplementation with active hexose correlated compound improves the antibody response to influenza B vaccine. Nutr Res. 2013;33(1):12-17. PubMed
  13. Uno, K., Kosuna, K., Sun, B., Fujii, H., Wakame, K., Chikumaru, S., Hosokawa, G., and Ueda, Y. Active Hexose Correlated Compound (AHCC) Improves Immunological Parameters and Performance Status of Patients with Solid Tumors. Biotherapy 2000;14(3):303-309.
  14. Ghoneum, M., Wimbley, M., Salem, F., McKlain, A., Attallah, N., and Gill, G. Immunomodulatory and anticancer effects of active hexose correlated compound (AHCC). Int J Immunother 1995;11:23-28.
  15. Sia, G. M. and Candlish, J. K. Effects of shiitake (Lentinus edodes) extract on human neutrophils and the U937 monocytic cell line. Phytother.Res. 1999;13(2):133-137. DOI
  16. Lobanok, A. G., Babitskaia, V. G., Plenina, L. V., Puchkova, T. A., and Osadchaia, O. V. [Composition and biological activity of submerged mycelium of the xylotrophic basidiomycete Lentinus edodes]. Prikl.Biokhim.Mikrobiol. 2003;39(1):69-73. DOI
  17. Liu, M., Li, J., Kong, F., Lin, J., and Gao, Y. Induction of immunomodulating cytokines by a new polysaccharide-peptide complex from culture mycelia of Lentinus edodes. Immunopharmacology 1998;40(3):187-198. PubMed
  18. Dai X, Stanilka JM, Rowe CA, et al. Consuming Lentinula edodes (Shiitake) Mushrooms Daily Improves Human Immunity: A Randomized Dietary Intervention in Healthy Young Adults. J Am Coll Nutr. 2015;34(6):478-87.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Shiitake Mushroom Also Interacts With Other Medications

Shiitake Mushroom has 311 moderate known drug interactions in our database — the Tofacitinib one above is one of them. If you take anything else, check it against the full list below.

Moderate 311 No known interaction 2,519 (incl. Tofacitinib)
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.

Everything else you take

See Every Supplement That Interacts With Tofacitinib

This page covers Shiitake Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tofacitinib page lists 184 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Active Hexose Correlated Compound (ahcc) (moderate).

By severity: 3 major · 143 moderate · 38 minor.

From our pharmacist’s overview on the Tofacitinib page

“Supplements deserve genuine care alongside tofacitinib (Xeljanz, Xeljanz XR), a medicine that deliberately dials down the immune system to control conditions like rheumatoid arthritis and ulcerative colitis. Most of the interactions on this page run through the liver enzymes that clear the drug, meaning an herb can push its blood level…”

Reviewed by 2 · Jul 18, 2026

Open the Tofacitinib 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. Your product may carry other ingredients that interact with Tofacitinib too, on top of Shiitake Mushroom — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Shiitake Mushroom and Tofacitinib 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 Tofacitinib
Steady interest

#1,607 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.

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.

Read the full Shiitake Mushroom monograph & all interactions
Medication

About Tofacitinib

What Is Tofacitinib Used For?

Brand names: Xeljanz, Xeljanz XR

  • Tofacitinib is used alone or with other medications to treat rheumatoid arthritis (condition in which the body attacks its own joints causing pain, swelling, and loss of function) in adults who are unable to take or did not respond to one or more tumor necrosis factor (TNF) inhibitor medication(s). It is also used to treat psoriatic arthritis (a condition that causes joint pain and swelling and scales on the skin) in adults who are unable to take or did not respond to or tolerate one or more TNF inhibitor medication(s). Tofacitinib is used to treat ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum) in adults who are unable to take or who did not respond to one or more TNF inhibitor medication(s). It is also used to treat polyarticular juvenile idiopathic arthritis (PJIA; a type of childhood arthritis that affects five or more joints during the first six months of the condition, causing pain, swelling, and loss of function) in children 2 years and older who are unable to take or who did not respond to one or more TNF inhibitor medication(s). Tofacitinib is in a class of medications called Janus kinase (JAK) inhibitors. It works by decreasing the activity of the immune system.

See full Tofacitinib 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
311Moderate
0Minor
2,518No known interaction
311 Moderate 2,518 No interaction
Moderate

311 interactions

Showing 60 of 311 moderate interactions — see all 311 on the Shiitake Mushroom page.

No interaction 2,518 drugs checked — show the list

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

Showing the 60 most looked-up of 2,518 medications checked with no known interaction — see the full Shiitake Mushroom list.

See the full Shiitake Mushroom interactions page
See every supplement checked against Tofacitinib, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

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

Keep exploring
Shiitake Mushroom monograph › Uses, safety, and every drug interaction in one place Tofacitinib supplement interactions › Every supplement checked against Tofacitinib, ranked by severity Tofacitinib drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Shiitake Mushroom and Tofacitinib Together: Common Questions

Can you take Shiitake Mushroom with Tofacitinib?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Shiitake Mushroom and Tofacitinib interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Tofacitinib and Shiitake Mushroom?

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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.