Drug & supplement interaction

Chaga + Methotrexate

Methotrexate brand names: Rheumatrex, Otrexup, Rasuvo, Reditrex.

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

We found no known interaction between Chaga and Methotrexate 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 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

Chaga and Methotrexate

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 Methotrexate and Chaga 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.

Chaga safety at a glance

Chaga overall Use caution Generally used in foods and teas, but human safety data are limited and a few risks have been reported.
Pregnancy Avoid Not enough safety information; best to avoid during pregnancy.
Breastfeeding Avoid Not enough safety information; best to avoid while breastfeeding.

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

Still wondering about combining Methotrexate and Chaga? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methotrexate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methotrexate is filed under 6 classifications — including organic anion-transporting polypeptide substrates (oatp), organic anion transporter 3 (oat3) substrates, hepatotoxic drugs. Chaga has documented interactions with 3 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and immunosuppressants (moderate) — and none of Methotrexate’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

Chaga Does Interact With Other Medications

Chaga has 327 moderate known drug interactions in our database — Methotrexate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 327 No known interaction 2,503 (incl. Methotrexate)
Taking anything else?

Check Another of Your Medications Against Chaga

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

What to actually watch for

No Interaction Found — But Data Suggests Chaga and Methotrexate May Share a Side Effect

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. One of them is worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on Additional detail

    Chaga

    “Orally, there have been two cases of kidney failure and one case of acute nephropathy related to excessive chaga consumption, which contains high concentrations of oxalate.”

    Chaga · Natural Medicines adverse-effect record, reported in kidney failure.

    3 sources cited
    1. 96566. Kikuchi Y, Seta K, Ogawa Y, et al. Chaga mushroom-induced oxalate nephropathy. Clin Nephrol 2014;81(6):440-4. PubMed
    2. 105246. Lee S, Lee HY, Park Y, et al. Development of end stage renal disease after long-term ingestion of chaga mushroom: case report and review of literature. J Korean Med Sci. 2020;35(19):e122.
    3. 108756. Kwon O, Kim Y, Paek JH, et al. Chaga mushroom-induced oxalate nephropathy that clinically manifested as nephrotic syndrome: A case report. Medicine (Baltimore) 2022;101(10):e28997. PubMed

    Methotrexate

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

Effects for Methotrexate come from the ADVERSE REACTIONS section of its FDA label; effects for Chaga come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 489,806 voluntary FDA FAERS reports for Methotrexate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Chaga or Methotrexate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Chaga or Methotrexate, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Methotrexate

This page covers Chaga only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methotrexate page lists 82 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Beer (major), Grapefruit (major) and Siberian Cocklebur (major).

By severity: 7 major · 60 moderate · 15 minor.

From our pharmacist’s overview on the Methotrexate page

“The liver is where methotrexate and supplements clash most. Methotrexate (Rheumatrex, Otrexup, Rasuvo), used for rheumatoid arthritis, psoriasis, and certain cancers, can strain the liver on its own, and 38 of the 82 interacting ingredients on this list add liver risk of their own, alcohol included, which makes this a list to approach…”

Reviewed by 2 · Jul 18, 2026

Open the Methotrexate interaction page

One more smart check

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

We hold 889 real supplement products containing Chaga, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chaga. Even though Chaga itself has no known interaction with Methotrexate, 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 Chaga and Methotrexate 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 Chaga
Top 25%

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

29 days ago today
Medication Methotrexate
Top 5%

#49 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 Chaga reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Chaga and Methotrexate 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 Chaga

What is Chaga?

  • Immune support
  • Antioxidant support
  • General wellness/tonic
  • Blood sugar support
  • Inflammation

Chaga is a fungus that grows mostly on birch trees and is used as a tea or supplement, mainly for immune and antioxidant support. Human evidence for its benefits is very limited, and it may raise some safety concerns such as effects on blood sugar, bleeding, and kidney stones. Talk with your pharmacist or doctor before using it, especially if you have a health condition or take other medicines.

Inonotus obliquus · Hymenochaetaceae · Sclerotium (the dark, hardened growth on the tree) · Tea, powder, capsules, tinctures, liquid extracts

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

Chaga: dosing

There is no standardized or officially established dose for Chaga. The amount in supplements and teas varies widely depending on the product and how it is prepared.The safest approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Chaga monograph & all interactions
Medication

About Methotrexate

What Is Methotrexate Used For?

Brand names: Rheumatrex, Otrexup, Rasuvo, Reditrex

Methotrexate treats a wide range of serious conditions. In cancer care, it is used for acute lymphoblastic leukemia, non-Hodgkin lymphoma, osteosarcoma, breast cancer, head and neck cancer, and gestational trophoblastic neoplasia (a rare tumor related to pregnancy). It is also used to prevent and treat meningeal leukemia (cancer affecting the lining of the brain and spinal cord).

Outside of cancer, methotrexate is prescribed for adults with rheumatoid arthritis (RA), children with polyarticular juvenile idiopathic arthritis (a form of childhood arthritis), and adults with severe psoriasis that hasn't responded well to other treatments.

Most-Reported Side Effects for Methotrexate

From FAERS, the FDA’s public side-effect reporting system (489,806 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Rheumatoid arthritis 42,798 reports
Arthralgia 40,830 reports
Fatigue 33,049 reports
Nausea 28,999 reports
Joint swelling 25,026 reports
See full Methotrexate drug information
Keep checking

Other Drugs & Chaga

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

0Major
327Moderate
0Minor
2,502No known interaction
327 Moderate 2,502 No interaction
Moderate

327 interactions

Showing 60 of 327 moderate interactions — see all 327 on the Chaga page.

No interaction 2,502 drugs checked — show the list

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

Showing the 60 most looked-up of 2,502 medications checked with no known interaction — see the full Chaga list.

See the full Chaga interactions page
See every supplement checked against Methotrexate, ranked by severity
Evidence & sources

Chaga References

The 9 references that drive our Chaga 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. Sun JE, Ao ZH, Lu ZM, et al. Antihyperglycemic and antilipidperoxidative effects of dry matter of culture broth of Inonotus obliquus in submerged culture on normal and alloxan-diabetes mice. J Ethnopharmacol 2008;118(1):7-13. PubMed
  2. Hyun KW, Jeong SC, Lee DH, et al. Isolation and characterization of a novel platelet aggregation inhibitory peptide from the medicinal mushroom, Inonotus obliquus. Peptides 2006;27(6):1173-8. PubMed
  3. Kim YO, Han SB, Lee HW, et al. Immuno-stimulating effect of the endo-polysaccharide produced by submerged culture of Inonotus obliquus. Life Sci 2005;77(19):2438-56. PubMed
  4. Kikuchi Y, Seta K, Ogawa Y, et al. Chaga mushroom-induced oxalate nephropathy. Clin Nephrol 2014;81(6):440-4. PubMed
  5. Lee S, Lee HY, Park Y, et al. Development of end stage renal disease after long-term ingestion of chaga mushroom: case report and review of literature. J Korean Med Sci. 2020;35(19):e122.
  6. Kwon O, Kim Y, Paek JH, et al. Chaga mushroom-induced oxalate nephropathy that clinically manifested as nephrotic syndrome: A case report. Medicine (Baltimore) 2022;101(10):e28997. PubMed
  7. Su L, Xin C, Yang J, et al. A polysaccharide from Inonotus obliquus ameliorates intestinal barrier dysfunction in mice with type 2 diabetes mellitus. Int J Biol Macromol 2022;214:312-323. PubMed
  8. Chen S, Ma Y, Li H, et al. Anti-diabetic e?ects of Inonotus obliquus extract in high fat diet combined streptozotocin-induced type 2 diabetic mice. Nutr Hosp 2022;39(6):1256-1263. PubMed
  9. Ye X, Wu K, Xu L, et al. Methanol extract of Inonotus obliquus improves type 2 diabetes mellitus through modifying intestinal flora. Front Endocrinol (Lausanne) 2023;13:1103972. 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 Chaga and Methotrexate Together: Common Questions

Is it safe to take Chaga with Methotrexate?
We do not list a known interaction between Chaga and Methotrexate. 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 Chaga and Methotrexate have any of the same side effects?
Yes — our sources link each of them separately to one 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.
How was the Chaga and Methotrexate combination checked?
Interactions in our licensed database are recorded against drug classes. Methotrexate is filed under 6 classifications, and Chaga has documented interactions with 3 drug classes — none of Methotrexate'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 Chaga interact with any other medications?
Yes. Chaga has 327 documented drug interactions in our database — Methotrexate 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 Methotrexate interact with any supplements?
Yes. Methotrexate has documented interactions with 82 supplements in our database — Chaga is not one of them. The Methotrexate 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

Chaga monograph Uses, safety profile, and every drug interaction in one place Methotrexate drug information The full plain-English guide to this medication Methotrexate supplement interactions Every supplement checked against Methotrexate, 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 9 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methotrexate and Chaga?

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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.