Drug & supplement interaction

Ergothioneine + Tofacitinib

Tofacitinib brand names: Xeljanz, Xeljanz XR.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Ergothioneine and Tofacitinib 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.

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Interaction report

Ergothioneine and Tofacitinib

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 Tofacitinib and Ergothioneine 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Ergothioneine at all — not against Tofacitinib, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Ergothioneine safety at a glance

Ergothioneine overall Use caution Appears well tolerated in foods and short-term studies, but long-term supplement safety is not well established.
Pregnancy Avoid There is not enough safety data on supplement doses during pregnancy, so it is best avoided.
Breastfeeding Avoid Safety while breastfeeding has not been studied, so avoid supplemental use.

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

Still wondering about combining Tofacitinib and Ergothioneine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Tofacitinib’s Own FDA Label Lists

This is not an interaction — none of it involves Ergothioneine. These are the most notable effects listed in the ADVERSE REACTIONS section of Tofacitinib’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 6 of them are worth acting on rather than waiting out — marked below.

  • Low blood sugar Worth acting on
  • Blood clots Worth acting on
  • A low white blood cell count Worth acting on
  • Liver problems Worth acting on
  • A higher chance of infection Worth acting on
  • An allergic reaction Worth acting on
  • Joint pain mentioned in 29.0% of FDA reports for Tofacitinib
  • Headache mentioned in 7.3% of FDA reports for Tofacitinib
  • Diarrhea
  • A skin rash

From the ADVERSE REACTIONS section of the FDA label for Tofacitinib. Read the label on DailyMed › Where a percentage is shown, it is the share of 185,980 voluntary FDA FAERS reports for Tofacitinib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Ergothioneine’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Ergothioneine side to compare — that is a limit of the record, not a statement that Ergothioneine has no side effects.

Overlapping uses

What Tofacitinib Is Prescribed For, and What Ergothioneine Has Been Studied For

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

Ergothioneine has been studied for:

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

    Ergothioneine for joint pain

    Preliminary clinical research shows that taking two capsules daily for 6 weeks of a specific product (ErgoFlex, Oxis International) containing ergothioneine 500 mcg, along with glucosamine, hyaluronic acid, glycosaminoglycans, collagen, acai, cat's claw, and willow bark has a moderate effect on pain when compared to baseline in patients with mild to moderate chronic joint pain.

    1 source cited
    1. 97669. Benson KF, Ager DM, Landes B, Aruoma OI, Jensen GS. Improvement of joint range of motion (ROM) and reduction of chronic pain after consumption of an ergothioneine-containing nutritional supplement. Prev Med. 2012;54 Suppl:S83-9. PubMed

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 Tofacitinib on your own; if you are taking Ergothioneine 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 Tofacitinib

This page covers Ergothioneine 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 Ergothioneine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 10 real supplement products containing Ergothioneine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ergothioneine. Even though Ergothioneine itself has no known interaction with Tofacitinib, 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 Ergothioneine 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 Ergothioneine
Steady interest

#1,153 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Tofacitinib
Top half

#975 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 Ergothioneine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Ergothioneine and Tofacitinib records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Ergothioneine

What is Ergothioneine?

  • Antioxidant support
  • Healthy aging and longevity
  • Cellular protection
  • Cognitive and brain health
  • General wellness

Ergothioneine is a naturally occurring amino acid–like compound (an antioxidant) found mostly in mushrooms and made by certain fungi and bacteria. Early laboratory studies suggest it may help protect cells from oxidative stress, but solid human evidence for any specific health benefit is still limited. It appears generally well tolerated, but if you are pregnant, breastfeeding, or taking other medicines, check with your pharmacist or doctor first.

Naturally found in certain mushrooms and other foods; produced by some fungi and bacteria · Capsules, tablets, powders, and as a nutrient in mushroom-based foods

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

Ergothioneine: dosing

There is no officially established dose for ergothioneine supplements. Doses used in research have varied, and a standard recommended amount has not been set.The safest approach is to follow the dosing on the product label and not exceed it. You can also increase your intake naturally by eating more mushrooms.

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

Read the full Ergothioneine 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 & Ergothioneine

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Ergothioneine list.

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

Ergothioneine References

The 2 references that drive our Ergothioneine 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. Benson KF, Ager DM, Landes B, Aruoma OI, Jensen GS. Improvement of joint range of motion (ROM) and reduction of chronic pain after consumption of an ergothioneine-containing nutritional supplement. Prev Med. 2012;54 Suppl:S83-9. PubMed
  2. Smith E, Ottosson F, Hellstrand S, et al. Ergothioneine is associated with reduced mortality and decreased risk of cardiovascular disease. Heart 2019. pii: heartjnl-2019-315485. 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 Ergothioneine and Tofacitinib Together: Common Questions

Is it safe to take Ergothioneine with Tofacitinib?
We do not list a known interaction between Ergothioneine and Tofacitinib. 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.
Are Ergothioneine and Tofacitinib 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 Ergothioneine in each. That is a conversation for your prescriber, especially if Tofacitinib is being adjusted to a target.
Does Tofacitinib interact with any supplements?
Yes. Tofacitinib has documented interactions with 184 supplements in our database — Ergothioneine is not one of them. The Tofacitinib 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

Ergothioneine monograph Uses, safety profile, and every drug interaction in one place Tofacitinib drug information The full plain-English guide to this medication Tofacitinib supplement interactions Every supplement checked against Tofacitinib, 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 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tofacitinib and Ergothioneine?

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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.