Drug & supplement interaction

Ergothioneine + Pemetrexed

Pemetrexed brand names: Alimta, Pemfexy.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Ergothioneine and Pemetrexed 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 Pemetrexed

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

What Pemetrexed’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 Pemetrexed’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.

  • High potassium Worth acting on
  • Low sodium Worth acting on
  • Low potassium Worth acting on
  • High blood sugar Worth acting on
  • A low platelet count Worth acting on
  • Kidney problems Worth acting on
  • Anemia Worth acting on
  • Shortness of breath Worth acting on
  • A low white blood cell count Worth acting on
  • A higher chance of infection Worth acting on

Showing the 10 most notable of 22 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 Pemetrexed. Read the label on DailyMed › 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 Pemetrexed

This page covers Ergothioneine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pemetrexed page lists 4 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: African Wild Potato (moderate), Banderol (moderate), Caffeic Acid (moderate) and Quercetin (moderate).

By severity: 4 moderate.

From our pharmacist’s overview on the Pemetrexed page

“Every supplement on file for pemetrexed (Alimta, Pemfexy) works the same way. Each can slow how the kidneys pull the drug out of the blood, which would let it linger and build to higher levels than intended.”

Reviewed by 2 · Jul 18, 2026

Open the Pemetrexed 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 Pemetrexed, 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 Pemetrexed 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 Pemetrexed
Top half

#711 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 Pemetrexed 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 Pemetrexed Injection

What Is Pemetrexed Injection Used For?

Brand names: Alimta, Pemfexy

Pemetrexed Injection is used for non-squamous non-small cell lung cancer (NSCLC) in several situations: as an initial treatment (combined with pembrolizumab and platinum chemotherapy, or with cisplatin alone), as a maintenance treatment after platinum-based chemotherapy, or as a single agent when the cancer has come back after prior chemotherapy. It is not used for squamous cell non-small cell lung cancer.

Pemetrexed Injection is also used, in combination with cisplatin, for the initial treatment of malignant pleural mesothelioma — a cancer of the lining of the lungs — in patients whose disease cannot be surgically removed or who are not good candidates for surgery.

Most-Reported Side Effects for Pemetrexed

From FAERS, the FDA’s public side-effect reporting system (37,889 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 3,095 reports
Anemia 2,134 reports
Nausea 1,906 reports
Diarrhea 1,824 reports
Pancytopenia 1,773 reports
See full Pemetrexed 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 Pemetrexed Together: Common Questions

Is it safe to take Ergothioneine with Pemetrexed?
We do not list a known interaction between Ergothioneine and Pemetrexed. 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 Pemetrexed interact with any supplements?
Yes. Pemetrexed has documented interactions with 4 supplements in our database — Ergothioneine is not one of them. The Pemetrexed 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 Pemetrexed 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.