Drug & supplement interaction

Eurycoma Longifolia + Lansoprazole

Lansoprazole brand name: Prevacid.

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

Eurycoma Longifolia has a minor interaction with Lansoprazole. Theoretically, Eurycoma longifolia might increase levels of CYP2C19 substrates.

Read the full interaction report
SeverityMinor
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Eurycoma Longifolia and Lansoprazole

Here is the interaction we found between these two, with the evidence behind it.

Minor

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

Why this applies to Lansoprazole

Lansoprazole falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Eurycoma Longifolia interacts with.

Theoretically, Eurycoma longifolia might increase levels of CYP2C19 substrates.
In vitro research suggests that methanolic Eurycoma longifolia root extract weakly inhibits CYP2C19 enzymes. This effect has not been reported in humans.
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 gist: your body uses an enzyme called CYP2C19 to break down lansoprazole. In lab dish studies, tongkat ali appears to weakly block that same enzyme. If that happened in real life, lansoprazole might clear a little more slowly and build up slightly, which in theory could nudge up its effects or mild side effects like headache, nausea, or diarrhea.

The important part: this is only theoretical. It comes from test-tube research and has never actually been shown in people, the effect was described as weak, and the rating here is minor. So I wouldn't lose sleep over it. Still, since supplement strengths vary a lot, it's worth mentioning to your pharmacist or doctor before combining the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Han YM, Kim IS, Rehman SU, Choe K, Yoo HH. In vitro evaluation of the effects of Eurycoma longifolia extract on CYP-mediated drug metabolism. Evid Based Complement Alternat Med 2015;2015:631329.

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

Eurycoma Longifolia Also Interacts With Other Medications

Eurycoma Longifolia has 3 moderate, 245 minor known drug interactions in our database — the Lansoprazole one above is one of them. If you take anything else, check it against the full list below.

Moderate 3 Minor 245 No known interaction 2,582 (incl. Lansoprazole)
Taking anything else?

Check Another of Your Medications Against Eurycoma Longifolia

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

From our Q&A

Questions About Eurycoma Longifolia or Lansoprazole

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Eurycoma Longifolia or Lansoprazole, 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 Lansoprazole

This page covers Eurycoma Longifolia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lansoprazole page lists 153 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 Adrafinil (moderate).

By severity: 3 major · 101 moderate · 49 minor.

From our pharmacist’s overview on the Lansoprazole page

“Heartburn and reflux send plenty of people toward both lansoprazole (Prevacid) and the supplement aisle, and that pairing calls for genuine care, since three of the 153 ingredients on file here carry major-rated interactions. Most of the list works through the liver enzymes that clear lansoprazole, either slowing them down (grapefruit,…”

Reviewed by 2 · Jul 18, 2026

Open the Lansoprazole interaction page

One more smart check

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

We hold 1,122 real supplement products containing Eurycoma Longifolia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Eurycoma Longifolia. Your product may carry other ingredients that interact with Lansoprazole too, on top of Eurycoma Longifolia — 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 Eurycoma Longifolia and Lansoprazole 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 Eurycoma Longifolia
Top 25%

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

29 days ago today
Medication Lansoprazole
Steady interest

#1,450 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 Eurycoma Longifolia

What is Eurycoma Longifolia?

Eurycoma Longifolia
  • Low testosterone or low libido in men
  • Male fertility support
  • Athletic performance and muscle strength
  • Energy and fatigue
  • Stress and mood
  • General male enhancement

Eurycoma longifolia (tongkat ali) is a Southeast Asian herb most popular for supporting testosterone, libido, and male fertility, with some small human studies suggesting possible benefits. However, the overall evidence is still limited and product quality varies widely, so talk with your pharmacist or doctor before using it, and avoid it if you are pregnant or breastfeeding.

Read the full Eurycoma Longifolia monograph & all interactions
Medication

About Lansoprazole

What Is Lansoprazole Used For?

Brand name: Prevacid

Lansoprazole lowers stomach acid. Prescription products are used for ulcers in the first part of the small intestine (duodenal ulcers) and in the stomach, for gastroesophageal reflux disease (GERD), and for erosive esophagitis (damage to the esophagus lining from acid).

It is also used with antibiotics to clear H. pylori infection, and for conditions where the stomach makes too much acid, such as Zollinger-Ellison syndrome. Certain over-the-counter lansoprazole capsules (such as Prevacid 24 HR) and tablets treat frequent heartburn, meaning heartburn on 2 or more days a week.

See full Lansoprazole drug information
Keep checking

Other Drugs & Eurycoma Longifolia

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

0Major
3Moderate
245Minor
2,581No known interaction
3 Moderate 245 Minor 2,581 No interaction
Moderate

3 interactions

Minor

245 interactions

Showing 60 of 245 minor interactions — see all 245 on the Eurycoma Longifolia page.

No interaction 2,581 drugs checked — show the list

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

Showing the 60 most looked-up of 2,581 medications checked with no known interaction — see the full Eurycoma Longifolia list.

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

Can you take Eurycoma Longifolia with Lansoprazole?
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.
How serious is the Eurycoma Longifolia and Lansoprazole 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 Lansoprazole and Eurycoma Longifolia?

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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.