Herb & supplement monograph

Eurycoma Longifolia Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Eurycoma Longifolia interacts with medications. The heart of this page is the interaction list — every drug Eurycoma Longifolia is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Eurycoma Longifolia is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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On this page

Interaction report

Drugs that interact with Eurycoma Longifolia

249 medications have a known interaction with Eurycoma Longifolia, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Eurycoma Longifolia using our pharmacist-reviewed interaction data.

AI summaries are generated from our Eurycoma Longifolia interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

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What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction 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.
Possible. 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
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Eurycoma Longifolia combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Eurycoma Longifolia affects

Every type of medication (drug category) Eurycoma Longifolia is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 5 drug categories Eurycoma Longifolia interacts with

Propranolol (inderal)Cytochrome P450 1a2 (cyp1a2) SubstratesCytochrome P450 2a6 (cyp2a6) SubstratesCytochrome P450 2c19 (cyp2c19) SubstratesTestosterone

Propranolol (Inderal)

Eurycoma longifolia can reduce the levels and clinical effects of propranolol.
A small clinical study in healthy persons shows that taking a single dose of a water-based Eurycoma longifolia extract 200 mg, in combination with a single dose of propranolol 80 mg, reduces the propranolol area under the curve (AUC) by 29%, reduces the peak concentration by 42%, and increases time to peak concentration by 86% when compared with control. Since the elimination half-life of propranolol did not change, it seems that Eurycoma longifolia alters the kinetics of propranolol by decreasing its absorption in the gut, and not by altering its metabolism. It is not known if separating administration will prevent this interaction.

Likelihood Probable Evidence A

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, Eurycoma longifolia might increase levels CYP1A2 substrates.
In vitro research suggests that methanolic Eurycoma longifolia root extract weakly inhibits CYP1A2 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2A6 (Cyp2A6) Substrates

Theoretically, Eurycoma longifolia might increase levels of CYP2A6 substrates.
In vitro research suggests that methanolic Eurycoma longifolia root extract weakly inhibits CYP2A6 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C19 (Cyp2C19) Substrates

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.

Likelihood Possible Evidence D

Testosterone

Theoretically, Eurycoma longifolia may further increase levels of testosterone.
A clinical study in aging males with testosterone levels below 300 ng/dL shows that taking a specific water extract of Eurycoma longifolia roots (Physta; Biotropics Malaysia) 100-200 mg daily with breakfast for 12 weeks increases total testosterone levels by 8% to 11% when compared with placebo. It is unclear whether this increase would occur in individuals with normal testosterone levels.

Likelihood Possible Evidence D

Monograph

Eurycoma Longifolia: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

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.

Scientific name: Eurycoma longifolia
Family: Simaroubaceae
Part used: Root (and root extracts)
Common forms: Capsules, tablets, powder, extracts, teas, and blended supplement products

People commonly use it for

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

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally tolerated short-term in studies, but long-term safety and product quality are uncertain.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using. Animal research suggests that there are no negative effects of Eurycoma longifolia on the of...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using. Animal research suggests that there are no negative effects of Eurycoma longifolia on the of...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Eurycoma longifolia is a flowering plant native to Southeast Asia, including Malaysia, Indonesia, Thailand, and Vietnam. It is best known by the name tongkat ali and is sometimes called "Malaysian ginseng." The plant's root has a long history of use in traditional medicine across the region.

People most often take it for so-called "male enhancement" reasons, such as boosting testosterone, libido, sexual function, and fertility. It is also marketed for energy, exercise performance, and stress. Today it is widely sold as capsules, powders, extracts, and as an ingredient in combination supplements.

How it works

Eurycoma longifolia contains compounds called quassinoids (such as eurycomanone) and other plant chemicals thought to be responsible for its effects.

The main proposed idea is that it may influence hormones — for example, by affecting how testosterone is released or freed from binding proteins in the blood. Researchers have also suggested possible antioxidant and stress-related effects. It is worth noting that much of this understanding comes from laboratory and animal studies, and the exact way it works in the human body is not fully understood.

Effectiveness

Does Eurycoma Longifolia work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 16 uses evaluated

1 Possibly effective 1 Leans ineffective 14 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Effective Sexual desire