Drug & supplement interaction

Epistane + Zileuton

Zileuton brand names: Zyflo, Zyflo CR.

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

Epistane has a moderate interaction with Zileuton. Theoretically, concomitant use might have additive adverse hepatotoxic effects.

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

Epistane and Zileuton

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Zileuton

Zileuton falls under HEPATOTOXIC DRUGS — the group Epistane interacts with.

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
Epistane is an anabolic androgenic steroid, and more specifically a 17-alpha-alkylated androgen. Therefore, there is concern that epistane has hepatotoxic effects. Also, epistane is structurally similar to epitiostanol, which has been associated with hepatotixicity in a case series of four patients.
Severity Moderate 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: Zileuton can be hard on your liver all by itself. That's why your doctor checks your liver enzymes with blood tests, especially during the first few months you take it. Epistane is a methylated anabolic steroid that is also known to stress the liver. Put the two together and you may be stacking one liver burden on top of another.

This concern is theoretical, based on how each one behaves rather than reports of this exact combo, so I don't want to scare you. Still, signs like yellowing skin or eyes, dark urine, belly pain, nausea, or unusual tiredness deserve quick attention. Honestly, I'd steer clear of Epistane entirely, and please loop in your doctor or pharmacist before mixing anything with Zileuton.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Rahnema CD, Crosnoe LE, Kim ED. Designer steroids - over-the-counter supplements and their androgenic component: review of an increasing problem. Andrology. 2015;3(2):150-5. PubMed
  2. Díaz FC, Sáez-González E, Benlloch S, et al. Albumin dialysis with MARS for the treatment of anabolic steroid-induced cholestasis. Ann Hepatol. 2016;15(6):939-943.

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

Epistane Also Interacts With Other Medications

Epistane has 369 moderate known drug interactions in our database — the Zileuton one above is one of them. If you take anything else, check it against the full list below.

Moderate 369 No known interaction 2,461 (incl. Zileuton)
Taking anything else?

Check Another of Your Medications Against Epistane

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

Everything else you take

See Every Supplement That Interacts With Zileuton

This page covers Epistane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Zileuton page lists 213 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 163 moderate · 44 minor.

Open the Zileuton interaction page

One more smart check

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

We hold 32 real supplement products containing Epistane, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Epistane. Your product may carry other ingredients that interact with Zileuton too, on top of Epistane — 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 Epistane and Zileuton 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 Epistane
Top half

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

29 days ago today
Medication Zileuton
Steady interest

#2,585 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 Epistane

What is Epistane?

  • Building muscle mass
  • Increasing strength
  • Cutting or losing body fat
  • Bodybuilding cycles

Epistane is a synthetic anabolic steroid (a methylated 'designer steroid'), not a true dietary supplement or herb, even though it has been sold as a 'prohormone.' It is liver-toxic, can disrupt your natural hormones, and is illegal to sell as a supplement in the US under the Designer Anabolic Steroid Control Act. We strongly recommend avoiding it and talking with a doctor or pharmacist.

Read the full Epistane monograph & all interactions
Medication

About Zileuton

What Is Zileuton Used For?

Brand names: Zyflo, Zyflo CR

Zileuton is used for the ongoing prevention and treatment of asthma in adults and adolescents aged 12 and older. It is a maintenance medicine — meaning it is taken regularly to keep asthma under control, not to stop an asthma attack once it has started.

Zyflo (the tablet form) and zileuton extended-release tablets are both approved for this same purpose. Neither form should be used to treat a sudden asthma attack. However, both can be continued during a flare-up of asthma while you also use your rescue inhaler.

See full Zileuton drug information
Keep checking

Other Drugs & Epistane

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

0Major
369Moderate
0Minor
2,460No known interaction
369 Moderate 2,460 No interaction
Moderate

369 interactions

Showing 60 of 369 moderate interactions — see all 369 on the Epistane page.

No interaction 2,460 drugs checked — show the list

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

Showing the 60 most looked-up of 2,460 medications checked with no known interaction — see the full Epistane list.

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

Can you take Epistane with Zileuton?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Epistane and Zileuton interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Zileuton and Epistane?

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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.