Drug & supplement interaction

Eurycoma Longifolia + Primaquine Phosphate

Primaquine Phosphate brand name: Primaquine.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Eurycoma Longifolia and Primaquine Phosphate 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

Eurycoma Longifolia and Primaquine Phosphate

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 Primaquine Phosphate and Eurycoma Longifolia 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.

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.

Eurycoma Longifolia safety at a glance

Eurycoma Longifoli... overall Use caution Generally tolerated short-term in studies, but long-term safety and product quality are uncertain.

Pregnancy Avoid Not enough safety data and possible hormonal effects, so avoid during pregnancy.

Breastfeeding Avoid No reliable safety information, so it is best to avoid while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Pharmacist analysis

Although there is no known interaction in this case, Eurycoma longifolia, most commonly known as Tongkat Ali, does have some potential interactions that are important to be aware of.

For example, it may interact with the following:

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES
CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES
CYTOCHROME P450 2A6 (CYP2A6) SUBSTRATES
Propranolol
Testosterone

Tongkat Ali has been reported to inhibit certain metabolizing enzymes in the liver (the ones mentioned above) and therefore, may increase the levels of substances metabolized by those enzymes. This could potentially affect the way these substances work or how long they stay in your system.

In regard to propranolol, some studies show that Tongkat Ali decreases how well propranolol is absorbed in the gut and could reduce its effects. It is not known if separating administration will prevent this interaction/

Lastly, testosterone, Tongkat Ali may theoretically further increase levels of testosterone, a hormone responsible for various functions in the body. You should be cautious combining the two.

— Dr. Brian Staiger, PharmD, BCPS

Still wondering about combining Primaquine Phosphate and Eurycoma Longifolia? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Primaquine Phosphate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Primaquine Phosphate is filed under 2 classifications — including oral drugs. Eurycoma Longifolia has documented interactions with 5 drug classes — the most serious being propranolol (inderal) (moderate), cytochrome p450 1a2 (cyp1a2) substrates (minor) and cytochrome p450 2a6 (cyp2a6) substrates (minor) — and none of Primaquine Phosphate’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Eurycoma Longifolia Does Interact With Other Medications

Eurycoma Longifolia has 3 moderate, 245 minor known drug interactions in our database — Primaquine Phosphate isn’t 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. Primaquine Phosphate)

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.

What to actually watch for

What Eurycoma Longifolia Itself Has Been Linked To

This is not an interaction — nothing below involves Primaquine Phosphate. It is the side-effect record for Eurycoma Longifolia on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Eurycoma Longifolia, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

Liver problems Worth acting on Additional detail
“Some research in both humans and animals suggests that Eurycoma longifolia might increase testosterone levels. If testosterone levels are increased beyond the normal range, there is risk of testosterone-related side effects which could include acne, insulin resistance, hepatotoxicity, and others.”

Eurycoma Longifolia · Natural Medicines adverse-effect record, reported in acne.
1 source cited

17924. Tambi MI, Imran MK, Henkel RR. Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism? Andrologia 2011 Jun 15. doi: 10.1111/j.1439-0272.2011.01168.x. [Epub ahead of pri PubMed
Acne Additional detail

Recorded for Eurycoma Longifolia in the same Natural Medicines adverse-effect record shown under Liver problems above.

Everything above comes from the Natural Medicines adverse-effect record for Eurycoma Longifolia — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Primaquine Phosphate’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Primaquine Phosphate column appears here.

Overlapping uses

What Primaquine Phosphate Is Prescribed For, and What Eurycoma Longifolia Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Primaquine Phosphate is a prescription medicine with approved uses on its FDA label. Eurycoma Longifolia is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Primaquine Phosphate is prescribed for: Primaquine Phosphate Tablets are used for the radical cure of vivax malaria — meaning they target and eliminate the dormant liver forms of the Plasmodium vivax parasite that can cause the infection to come back (relapse). This is different from treating the active blood-stage infection, which is usually handled first with another medicine like chloroquine. Primaquine Phosphate Tablets are also used after a course of chloroquine suppressive therapy in areas where vivax malaria is common, to prevent relapse once that preventive treatment ends.

Eurycoma Longifolia has been studied for:

Malaria studied, not established Eurycoma Longifolia has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Eurycoma Longifolia for malaria

Although there is interest in using oral Eurycoma longifolia for malaria, there is insufficient reliable information about the clinical effects of Eurycoma longifolia for this condition.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Primaquine Phosphate on your own; if you are taking Eurycoma Longifolia for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Primaquine Phosphate

This page covers Eurycoma Longifolia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Primaquine Phosphate page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Grapefruit (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Primaquine Phosphate page

“Activated charcoal, the only major-rated interaction among the 18 on file, can bind primaquine phosphate (Primaquine) in the gut and shrink how much of each dose your body actually absorbs. That matters more than usual, because this antimalarial exists to wipe out the malaria parasites hiding in the liver, and an under-absorbed course…”

Reviewed by 2 · Jul 18, 2026

Open the Primaquine Phosphate 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. Even though Eurycoma Longifolia itself has no known interaction with Primaquine Phosphate, 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 Eurycoma Longifolia and Primaquine Phosphate 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 10%

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

29 days ago today

Medication Primaquine Phosphate

Steady interest

#2,624 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 Eurycoma Longifolia reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Eurycoma Longifolia and Primaquine Phosphate records this page draws on were last updated July 10, 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Eurycoma Longifolia

What is 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.

Eurycoma longifolia · Simaroubaceae · Root (and root extracts) · Capsules, tablets, powder, extracts, teas, and blended supplement products

An interaction check asks whether these two react with each other — it does not ask whether Eurycoma Longifolia is a good idea for someone in your situation. Here is what our Eurycoma Longifolia record says about it on its own.

Eurycoma Longifolia: dosing

There is no official or universally agreed-upon dose for Eurycoma longifolia. Studies have used different standardized extracts at different strengths, which makes it hard to recommend one specific amount.The best approach is to follow the directions on the product label and not exceed them.

From our Eurycoma Longifolia monograph — the full record covers uses, side effects and every documented interaction.

Read the full Eurycoma Longifolia monograph & all interactions

Medication

About Primaquine

What Is Primaquine Used For?

Brand name: Primaquine

Primaquine Phosphate Tablets are used for the radical cure of vivax malaria — meaning they target and eliminate the dormant liver forms of the Plasmodium vivax parasite that can cause the infection to come back (relapse). This is different from treating the active blood-stage infection, which is usually handled first with another medicine like chloroquine.

Primaquine Phosphate Tablets are also used after a course of chloroquine suppressive therapy in areas where vivax malaria is common, to prevent relapse once that preventive treatment ends.

See full Primaquine 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 Primaquine Phosphate, ranked by severity

Evidence & sources

Eurycoma Longifolia References

The 4 references that drive our Eurycoma Longifolia 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.

Salman SA, Amrah S, Wahab MS, et al. Modification of propranolol's bioavailability by Eurycoma longifolia water-based extract. J Clin Pharm Ther 2010;35:691-6. PubMed
Tambi MI, Imran MK, Henkel RR. Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism? Andrologia 2011 Jun 15. doi: 10.1111/j.1439-0272.2011.01168.x. [Epub ahead of pri PubMed
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.
Chinnappan SM, George A, Pandey P, Narke G, Choudhary YK. Effect of Eurycoma longifolia standardised aqueous root extract-Physta ® on testosterone levels and quality of life in ageing male subjects: a randomised, double-blind, placebo-controlled multicent

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 Eurycoma Longifolia and Primaquine Phosphate Together: Common Questions

Is it safe to take Eurycoma Longifolia with Primaquine Phosphate?

We do not list a known interaction between Eurycoma Longifolia and Primaquine Phosphate. 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.

Are Eurycoma Longifolia and Primaquine Phosphate used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Eurycoma Longifolia in each. That is a conversation for your prescriber, especially if Primaquine Phosphate is being adjusted to a target.

How was the Eurycoma Longifolia and Primaquine Phosphate combination checked?

Interactions in our licensed database are recorded against drug classes. Primaquine Phosphate is filed under 2 classifications, and Eurycoma Longifolia has documented interactions with 5 drug classes — none of Primaquine Phosphate's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Eurycoma Longifolia interact with any other medications?

Yes. Eurycoma Longifolia has 248 documented drug interactions in our database — Primaquine Phosphate is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Primaquine Phosphate interact with any supplements?

Yes. Primaquine Phosphate has documented interactions with 18 supplements in our database — Eurycoma Longifolia is not one of them. The Primaquine Phosphate interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Eurycoma Longifolia monograph Uses, safety profile, and every drug interaction in one place Primaquine drug information The full plain-English guide to this medication Primaquine Phosphate supplement interactions Every supplement checked against Primaquine Phosphate, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Primaquine Phosphate 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.