Drug & supplement interaction

Testolone + Interferon Beta-1a

Interferon Beta-1a brand names: Rebif, Avonex.

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

Testolone has a moderate interaction with Interferon Beta-1a. Theoretically, concomitant use might have additive hepatotoxic effects.

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

Testolone and Interferon Beta-1a

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Interferon Beta-1a

Interferon Beta-1a falls under HEPATOTOXIC DRUGS — the group Testolone interacts with.

Theoretically, concomitant use might have additive hepatotoxic effects.
In a case report, a 52-year-old male was diagnosed with liver injury thought to be related to the use of products containing testolone. Also, elevated liver enzymes were commonly reported in a dose escalation study of testolone.
Severity Moderate Likelihood Possible Evidence B

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: both of these can be hard on your liver, so using them together may stack up that stress. Interferon beta-1a (Rebif, Avonex) is known to raise liver enzymes and, less often, cause real liver injury, which is why your doctor checks bloodwork while you're on it. Testolone (RAD-140) has been tied to liver enzyme bumps and at least one case of liver injury, so adding it gives your liver a second hit.

This is an additive concern, not Testolone changing how your MS medicine works. Watch for warning signs like yellowing skin or eyes, dark urine, belly pain, or unusual tiredness. Honestly, Testolone isn't an approved or proven-safe product, so please talk with your doctor or pharmacist before mixing anything with your interferon.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. LoRusso P, Hamilton E, Ma C, et al. A first-in-human phase 1 study of a novel selective androgen receptor modulator (SARM), RAD140, in ER+/HER2- metastatic breast cancer. Clin Breast Cancer 2022;22(1):67-77. PubMed
  2. Barbara M, Dhingra S, Mindikoglu AL. Drug-induced liver injury associated with alpha bolic (RAD-140) and alpha elite (RAD-140 and LGD-4033). ACG Case Rep J 2020;7(6):e00409. PubMed

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

Testolone Also Interacts With Other Medications

Testolone has 369 moderate known drug interactions in our database — the Interferon Beta-1a 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. Interferon Beta-1a)
Taking anything else?

Check Another of Your Medications Against Testolone

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

Everything else you take

See Every Supplement That Interacts With Interferon Beta-1a

This page covers Testolone only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Beta-1a page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 3 major · 53 moderate · 1 minor.

From our pharmacist’s overview on the Interferon Beta-1a page

“Siberian cocklebur, an herb tied to documented cases of liver failure, is the first name to know for anyone injecting interferon beta-1a (Rebif, Avonex) for multiple sclerosis. Interferon beta-1a can strain the liver on its own, which is why prescribers order routine liver blood tests, and 38 of the 57 supplements on file carry that sa…”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Beta-1a interaction page

One more smart check

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

We hold 9 real supplement products containing Testolone, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Testolone. Your product may carry other ingredients that interact with Interferon Beta-1a too, on top of Testolone — 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 Testolone and Interferon Beta-1a 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 Testolone
Top half

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

29 days ago today
Medication Interferon Beta-1a
Top half

#1,110 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 Testolone

What is Testolone?

  • Muscle building
  • Athletic performance and bodybuilding
  • Strength gains
  • Body recomposition (fat loss with muscle gain)

Testolone (RAD-140) is a synthetic experimental drug called a selective androgen receptor modulator (SARM), not a dietary supplement or herb, and it is not approved or proven safe for human use. It is illegally sold for muscle building, has been linked to serious harms including liver injury, and is banned in sports — it should not be taken outside of supervised clinical research.

Read the full Testolone monograph & all interactions
Medication

About Interferon Beta-1a Intramuscular Injection

What Is Interferon Beta-1a Intramuscular Injection Used For?

Brand names: Rebif, Avonex

  • Interferon beta-1a intramuscular injection is used to treat adults with various forms of multiple sclerosis (MS; a disease in which the nerves do not function properly and people may experience weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control) including:

    • clinically isolated syndrome (CIS; nerve symptom episodes that last at least 24 hours),

    • relapsing-remitting forms (course of disease where symptoms flare up from time to time), or

    • secondary progressive forms (course of disease where relapses occur more often).

  • Interferon beta-1a is in a class of medications called immunomodulators. It works by decreasing inflammation and preventing nerve damage that may cause symptoms of multiple sclerosis.

See full Interferon Beta-1a Intramuscular Injection drug information
Keep checking

Other Drugs & Testolone

Browse every other medication we’ve checked against Testolone — 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 Testolone page.

No interaction 2,460 drugs checked — show the list

We also checked Testolone 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 Testolone list.

See the full Testolone interactions page
See every supplement checked against Interferon Beta-1a, 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
Testolone monograph › Uses, safety, and every drug interaction in one place Interferon Beta-1a supplement interactions › Every supplement checked against Interferon Beta-1a, ranked by severity Interferon Beta-1a Intramuscular Injection 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 Testolone and Interferon Beta-1a Together: Common Questions

Can you take Testolone with Interferon Beta-1a?
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 Testolone and Interferon Beta-1a 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 Interferon Beta-1a and Testolone?

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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.