Drug & supplement interaction

Ergothioneine + Gemcitabine

Gemcitabine brand name: Gemzar.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Ergothioneine and Gemcitabine 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 Gemcitabine

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 Gemcitabine 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 Gemcitabine, 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 Gemcitabine and Ergothioneine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Gemcitabine’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 Gemcitabine’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. 10 of them are worth acting on rather than waiting out — marked below.

  • A stroke or mini-stroke Worth acting on
  • A heart attack Worth acting on
  • A low platelet count Worth acting on mentioned in 7.0% of FDA reports for Gemcitabine
  • An irregular heartbeat Worth acting on
  • Anemia Worth acting on mentioned in 5.8% of FDA reports for Gemcitabine
  • A low white blood cell count Worth acting on mentioned in 6.2% of FDA reports for Gemcitabine
  • Kidney problems Worth acting on
  • Raised blood pressure Worth acting on
  • Shortness of breath Worth acting on
  • Liver problems Worth acting on

Showing the 10 most notable of 16 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Gemcitabine. Read the label on DailyMed › Where a percentage is shown, it is the share of 53,020 voluntary FDA FAERS reports for Gemcitabine 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.

Everything else you take

See Every Supplement That Interacts With Gemcitabine

This page covers Ergothioneine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Gemcitabine page lists 39 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Ashwagandha (moderate) and Black Cohosh (moderate).

By severity: 3 major · 35 moderate · 1 minor.

Open the Gemcitabine 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 Gemcitabine, 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 Gemcitabine 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

#1,171 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Gemcitabine
Steady interest

#2,588 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 Gemcitabine 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 Gemcitabine Injection

What Is Gemcitabine Injection Used For?

Brand name: Gemzar

Gemcitabine Injection (available as Avgemsi, Gemcitabine, and Infugem) is used to treat several types of cancer. It is given in combination with carboplatin for advanced ovarian cancer that has returned at least 6 months after platinum-based treatment, and in combination with paclitaxel as a first-line treatment for metastatic breast cancer after prior chemotherapy with an anthracycline (a specific class of chemo drug).

It is also given in combination with cisplatin for non-small cell lung cancer (NSCLC) that cannot be removed surgically or has spread. For pancreatic cancer that is locally advanced or has spread, it is used as a single agent — including in patients who have already been treated with fluorouracil.

Most-Reported Side Effects for Gemcitabine

From FAERS, the FDA’s public side-effect reporting system (53,020 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Disease progression 4,850 reports
Thrombocytopenia 3,706 reports
Neutropenia 3,295 reports
Anemia 3,084 reports
Malignant neoplasm progression 2,912 reports
See full Gemcitabine Injection 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
No interaction 2,829 drugs checked — show the list
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 Gemcitabine Together: Common Questions

Is it safe to take Ergothioneine with Gemcitabine?
We do not list a known interaction between Ergothioneine and Gemcitabine. 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.
Does Gemcitabine interact with any supplements?
Yes. Gemcitabine has documented interactions with 39 supplements in our database — Ergothioneine is not one of them. The Gemcitabine 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 Gemcitabine and Ergothioneine?

Our pharmacists answer your medication & supplement questions — free.

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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.