Drug & supplement interaction

Eurycoma Longifolia + Diethylstilbestrol, Methyltestosterone

Diethylstilbestrol, Methyltestosterone brand name: Tylosterone.

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

Eurycoma Longifolia has a minor interaction with Diethylstilbestrol, Methyltestosterone. Theoretically, Eurycoma longifolia may further increase levels of testosterone.

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

Eurycoma Longifolia and Diethylstilbestrol, Methyltestosterone

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

Minor

TESTOSTERONE

Why this applies to Diethylstilbestrol, Methyltestosterone

Diethylstilbestrol, Methyltestosterone falls under TESTOSTERONE — the group Eurycoma Longifolia interacts with.

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.
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 simple version: your medication Tylosterone contains methyltestosterone, which is a form of testosterone. Tongkat ali (Eurycoma longifolia) is taken specifically to nudge testosterone levels up a little. So in theory, you'd be pushing in the same direction from two sources at once, which could mean slightly more testosterone-type effects than you bargained for.

To be clear, this is a theoretical concern based on how the herb works, not on hard evidence with this exact medicine, and the studied bumps in testosterone were modest (around 8 to 11 percent). Still, if you'd ever notice more of testosterone's typical effects (oily skin or acne, mood shifts, fluid retention), this is the kind of thing to mention. Since this combo is genuinely 'why are you taking both?' territory, please run it by your doctor or pharmacist before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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

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, 244 minor known drug interactions in our database — the Diethylstilbestrol, Methyltestosterone one above is one of them. If you take anything else, check it against the full list below.

Moderate 3 Minor 244 No known interaction 2,583 (incl. Diethylstilbestrol, Methyltestosterone)
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.

Everything else you take

See Every Supplement That Interacts With Diethylstilbestrol, Methyltestosterone

This page covers Eurycoma Longifolia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diethylstilbestrol, Methyltestosterone page lists 73 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and 1-androsterone (moderate).

By severity: 4 major · 53 moderate · 16 minor.

From our pharmacist’s overview on the Diethylstilbestrol, Methyltestosterone page

“Tylosterone pairs diethylstilbestrol, an estrogen, with methyltestosterone, an oral androgen already known for stressing the liver, and that is exactly where this interaction list concentrates. I would handle these 73 supplements carefully.”

Reviewed by 2 · Jul 18, 2026

Open the Diethylstilbestrol, Methyltestosterone 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 Diethylstilbestrol, Methyltestosterone 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 Diethylstilbestrol, Methyltestosterone 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%

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

29 days ago today
Medication Diethylstilbestrol, Methyltestosterone
Steady interest

#2,636 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
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
244Minor
2,582No known interaction
3 Moderate 244 Minor 2,582 No interaction
Moderate

3 interactions

Minor

244 interactions

Showing 60 of 244 minor interactions — see all 244 on the Eurycoma Longifolia page.

No interaction 2,582 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 2,582 medications checked with no known interaction — see the full Eurycoma Longifolia list.

See the full Eurycoma Longifolia interactions page
See every supplement checked against Diethylstilbestrol, Methyltestosterone, 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 Diethylstilbestrol, Methyltestosterone supplement interactions › Every supplement checked against Diethylstilbestrol, Methyltestosterone, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Eurycoma Longifolia and Diethylstilbestrol, Methyltestosterone Together: Common Questions

Can you take Eurycoma Longifolia with Diethylstilbestrol, Methyltestosterone?
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 Diethylstilbestrol, Methyltestosterone 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 Diethylstilbestrol, Methyltestosterone 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.