Drug & supplement interaction

Yerba Mate + Osimertinib Mesylate

Osimertinib Mesylate brand name: Tagrisso.

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

Osimertinib Mesylate falls into 2 drug categories that Yerba Mate can interact with; the most serious is rated minor. Theoretically, concomitant use of CYP1A2 inhibitors and yerba mate might increase levels and adverse effects of the caffeine in yerba mate.

Read the full interaction report
SeverityMinor
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Yerba Mate and Osimertinib Mesylate

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Yerba Mate interacts with whole categories of medication. Osimertinib Mesylate falls into 2 of those categories, so it can interact with Yerba Mate in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Minor).

Minor

CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS

1 of 2

Why this applies to Osimertinib Mesylate

Osimertinib Mesylate falls under CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS — the group Yerba Mate interacts with.

Theoretically, concomitant use of CYP1A2 inhibitors and yerba mate might increase levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Caffeine is metabolized by CYP1A2. Theoretically, drugs that inhibit CYP1A2 may decrease the rate of caffeine clearance and increase caffeine levels.
Severity Minor 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 a helpful thing to understand about this pairing: it's not your osimertinib (Tagrisso) that gets affected here, it's the caffeine in the yerba mate. Osimertinib can mildly slow down an enzyme called CYP1A2, which is the same one your body uses to clear caffeine. So in theory, the caffeine from your mate might hang around a little longer and feel a bit stronger.

In real life, that could mean more jitters, a racing heart, trouble sleeping, or feeling wired if you drink a lot of mate. This is only a theoretical concern based on how the enzyme works, and it's rated as minor, so an occasional cup is unlikely to cause trouble. Your osimertinib still works the same. If you notice more caffeine-like side effects, just cut back and mention it to your pharmacist or oncologist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63. PubMed
  2. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Osimertinib Mesylate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, yerba mate might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that yerba mate extract inhibits CYP3A4 enzymes. Theoretically, taking yerba mate may increase levels and adverse effects of CYP3A4 substrates.
Severity Minor 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 basic idea: your body uses an enzyme called CYP3A4 to help clear osimertinib (Tagrisso). Lab studies suggest yerba mate can mildly slow that enzyme down. In theory, that could let a little more osimertinib build up in your system, which might nudge up its usual side effects like diarrhea, mouth sores, dry or itchy skin, nail changes, or fatigue.

I want to be honest about how soft this signal is. This comes only from test-tube research, not real patients, and it's rated as a minor interaction. A cup or two of mate is unlikely to cause trouble. Still, since osimertinib is a serious cancer medicine, it's worth a quick chat with your oncology team or pharmacist before adding regular or concentrated mate, just so everyone's on the same page.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Feltrin C, Farias IV, Sandjo LP, Reginatto FH, Simões CMO. Effects of Standardized Medicinal Plant Extracts on Drug Metabolism Mediated by CYP3A4 and CYP2D6 Enzymes. Chem Res Toxicol 2020;33(9):2408-2419. PubMed

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

Yerba Mate Also Interacts With Other Medications

Yerba Mate has 8 major, 505 moderate, 572 minor known drug interactions in our database — the Osimertinib Mesylate one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 505 Minor 572 No known interaction 1,745 (incl. Osimertinib Mesylate)
Taking anything else?

Check Another of Your Medications Against Yerba Mate

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

From our Q&A

Questions About Yerba Mate or Osimertinib Mesylate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Yerba Mate or Osimertinib Mesylate, 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 Osimertinib Mesylate

This page covers Yerba Mate only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Osimertinib Mesylate page lists 164 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 8 major · 117 moderate · 39 minor.

From our pharmacist’s overview on the Osimertinib Mesylate page

“Osimertinib (Tagrisso) treats EGFR-mutated lung cancer, and this is a list to read carefully before you add anything from the supplement aisle. Of the 164 ingredients on file, most can change how much drug reaches your blood, chiefly through the CYP3A4 enzyme that clears it.”

Reviewed by 2 · Jul 18, 2026

Open the Osimertinib Mesylate interaction page

One more smart check

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

We hold 68 real supplement products containing Yerba Mate, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Yerba Mate. Your product may carry other ingredients that interact with Osimertinib Mesylate too, on top of Yerba Mate — 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 Yerba Mate and Osimertinib Mesylate 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 Yerba Mate
Steady interest

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

29 days ago today
Medication Osimertinib Mesylate
Top half

#1,372 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 Yerba Mate

What is Yerba Mate?

Yerba Mate
  • Energy and alertness
  • Weight loss
  • Mental focus
  • Digestive support
  • Antioxidant support

Yerba mate is a caffeine-containing herbal beverage from South America that is widely enjoyed for its stimulating, coffee-like effects. While it is rich in antioxidants and is being studied for weight, blood sugar, and cholesterol, strong human evidence for most health claims is limited. Drinking very hot mate over many years has been linked to higher risk of certain cancers, so enjoy it warm and in moderation.

Read the full Yerba Mate monograph & all interactions
Medication

About Osimertinib

What Is Osimertinib Used For?

Brand name: Tagrisso

Tagrisso is used to treat adults with non-small cell lung cancer (NSCLC) whose tumors have specific EGFR mutations — either an exon 19 deletion or an exon 21 L858R mutation — confirmed by an FDA-approved test. It is used in several settings: after surgery to reduce the risk of cancer returning (adjuvant therapy), for locally advanced stage III NSCLC that has not progressed after chemoradiation, and as a first-line treatment for locally advanced or metastatic NSCLC (including in combination with pemetrexed and platinum-based chemotherapy).

Tagrisso is also approved for adults with metastatic NSCLC that carries a specific resistance mutation called T790M, when the cancer has stopped responding to another EGFR-targeted therapy.

See full Osimertinib drug information
Keep checking

Other Drugs & Yerba Mate

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

8Major
505Moderate
572Minor
1,744No known interaction
8 Major 505 Moderate 572 Minor 1,744 No interaction
Major

8 interactions

Moderate

505 interactions

Showing 60 of 505 moderate interactions — see all 505 on the Yerba Mate page.

Minor

572 interactions

Showing 60 of 572 minor interactions — see all 572 on the Yerba Mate page.

No interaction 1,744 drugs checked — show the list

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

Showing the 60 most looked-up of 1,744 medications checked with no known interaction — see the full Yerba Mate list.

See the full Yerba Mate interactions page
See every supplement checked against Osimertinib Mesylate, 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
Yerba Mate monograph › Uses, safety, and every drug interaction in one place Osimertinib Mesylate supplement interactions › Every supplement checked against Osimertinib Mesylate, ranked by severity Osimertinib 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 Yerba Mate and Osimertinib Mesylate Together: Common Questions

Can you take Yerba Mate with Osimertinib Mesylate?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Yerba Mate and Osimertinib Mesylate?
Osimertinib Mesylate belongs to more than one drug category, and Yerba Mate interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Yerba Mate and Osimertinib Mesylate interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Osimertinib Mesylate and Yerba Mate?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.