Drug & supplement interaction

Testolone + Belumosudil Mesylate

Belumosudil Mesylate brand name: Rezurock.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Testolone and Belumosudil Mesylate 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. Additionally, although there is no interaction, the label for Belumosudil Mesylate states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Testolone and Belumosudil Mesylate

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 Belumosudil Mesylate and Testolone 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.

Testolone safety at a glance

Testolone overall Avoid Testolone is an unapproved experimental drug with reported serious risks and should not be used.
Pregnancy Possibly Unsafe When used orally. The U.S. Food and Drug Administration and other regulatory agencies warn that dietary supplements containing selective androgen receptor modul... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. The U.S. Food and Drug Administration and other regulatory agencies warn that dietary supplements containing selective androgen receptor modul... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Belumosudil Mesylate and Testolone? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Belumosudil Mesylate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Belumosudil Mesylate is filed under 2 classifications — cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Testolone has documented interactions with 1 drug class — the most serious being hepatotoxic drugs (moderate) — and none of Belumosudil Mesylate’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

Testolone Does Interact With Other Medications

Testolone has 370 moderate known drug interactions in our database — Belumosudil Mesylate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 370 No known interaction 2,460 (incl. Belumosudil Mesylate)
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.

What to actually watch for

No Interaction Found — But Data Suggests Testolone and Belumosudil Mesylate May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 2 of them are worth acting on rather than waiting out — marked below.

  • Shortness of breath Worth acting on Additional detail

    Testolone

    “Acute myocarditis presumably associated with testolone has been reported in a 32-year-old male who used the product for athletic performance enhancement. The patient presented with shortness of breath and a mild fever, with elevations in troponin I, B-type natriuretic peptide, erythrocyte sedimentation rate, C-reactive protein, and D-dimer and received treatment with aspirin, atorvastatin, carvedilol, and furosemide,…”

    Testolone · Natural Medicines adverse-effect record, reported in athletic performance.

    5 sources cited
    1. 108161. Padappayil RP, Chandini Arjun A, Vivar Acosta J, Ghali W, Mughal MS. Acute myocarditis from the use of selective androgen receptor modulator (SARM) RAD-140 (Testolone). Cureus. 2022;14(1):e21663. PubMed
    2. 94879. Warning Letter: Ironmag Labs 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm582464.htm Accessed: November 1, 2017
    3. 94880. Warning Letter: Panther Sports Nutrition 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm581630.htm. Accessed: November 1, 2017
    4. 94881. Warning Letter: Infantry Labs LLC 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm582685.htm. Accessed: November 1, 2017
    5. 108159. 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

    Belumosudil Mesylate

    Listed in the ADVERSE REACTIONS section of the FDA label for Belumosudil Mesylate. Read the label on DailyMed ›

  • Liver problems Worth acting on Additional detail

    Testolone

    “A dose escalation study of testolone 50-150 mg daily for about 8 weeks found that the most common treatment-emergent adverse events included moderate elevations in aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin.”

    Testolone · Natural Medicines adverse-effect record, reported in diarrhea.

    5 sources cited
    1. 108159. 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. 108160. 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
    3. 94879. Warning Letter: Ironmag Labs 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm582464.htm Accessed: November 1, 2017
    4. 94880. Warning Letter: Panther Sports Nutrition 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm581630.htm. Accessed: November 1, 2017
    5. 94881. Warning Letter: Infantry Labs LLC 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm582685.htm. Accessed: November 1, 2017

    Belumosudil Mesylate

    Listed in the ADVERSE REACTIONS section of the FDA label for Belumosudil Mesylate. Read the label on DailyMed ›

  • Reduced appetite / Vomiting Additional detail

    Testolone

    “Orally, vomiting and decreased appetite were reported to be some of the most common adverse effects in a dose escalation study of testolone 50-150 mg daily for about 8 weeks.”

    Testolone · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    1 source cited
    1. 108159. 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

    Belumosudil Mesylate

    Listed in the ADVERSE REACTIONS section of the FDA label for Belumosudil Mesylate. Read the label on DailyMed ›

  • Fever Additional detail

    Testolone

    Recorded for Testolone in the same Natural Medicines adverse-effect record shown under Shortness of breath above.

    Belumosudil Mesylate

    Listed in the ADVERSE REACTIONS section of the FDA label for Belumosudil Mesylate. Read the label on DailyMed ›

  • Itching / Diarrhea Additional detail

    Testolone

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

    Belumosudil Mesylate

    Listed in the ADVERSE REACTIONS section of the FDA label for Belumosudil Mesylate. Read the label on DailyMed ›

Reported for Testolone but not commonly for Belumosudil Mesylate: a heart attack, weight loss, a fast or pounding heartbeat and weight gain.

Effects for Belumosudil Mesylate come from the ADVERSE REACTIONS section of its FDA label; effects for Testolone come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Testolone in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. The U.S. Food and Drug Administration and other regulatory agencies warn that dietary supplements containing selective androgen receptor modulators (SARMs) are dangerous. Avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Belumosudil Mesylate Products Have a Food Rule — Testolone Should Not Break It

At least one FDA label for a product containing Belumosudil Mesylate says to take it with food. If you take Testolone on an empty stomach out of habit, keep them separate — and take Belumosudil Mesylate with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Belumosudil Mesylate products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION Recommended Dosage : 200 mg taken orally once daily with food.

From the Dosage and Administration section of the FDA label we read for Belumosudil Mesylate — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Belumosudil Mesylate

This page covers Testolone only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Belumosudil Mesylate page lists 138 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 94 moderate · 41 minor.

From our pharmacist’s overview on the Belumosudil Mesylate page

“Most people taking belumosudil (Rezurock) are managing chronic graft-versus-host disease after a stem cell transplant, and many reach for supplements hoping for extra support. This list warrants real vigilance.”

Reviewed by 2 · Jul 18, 2026

Open the Belumosudil Mesylate 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. Even though Testolone itself has no known interaction with Belumosudil Mesylate, 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 Testolone and Belumosudil Mesylate 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

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

29 days ago today
Medication Belumosudil Mesylate
Top half

#746 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 Testolone reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Testolone and Belumosudil Mesylate 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 .
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.

Synthetic compound (not a plant); supplied as a chemical powder or liquid · Capsules, tablets, liquids, and powders sold as 'research chemicals'

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

Testolone: dosing

There is no established safe or approved dose of Testolone. It has not gone through the testing needed to set safe dosing guidelines for people.Doses listed on illegally sold products are not verified, and the actual content of these products is often unreliable. For these reasons, we do not provide dosing information.The safest choice is not to use Testolone.

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

Read the full Testolone monograph & all interactions
Medication

About Belumosudil

What Is Belumosudil Used For?

Brand name: Rezurock

Rezurock (belumosudil) is used to treat chronic graft-versus-host disease (chronic GVHD) — a serious immune condition that can occur after a stem cell or bone marrow transplant, where the donor's immune cells attack the recipient's body. It is specifically for patients aged 12 and older whose chronic GVHD has not responded to at least two prior systemic (whole-body) treatments.

See full Belumosudil 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
370Moderate
0Minor
2,459No known interaction
370 Moderate 2,459 No interaction
Moderate

370 interactions

Showing 60 of 370 moderate interactions — see all 370 on the Testolone page.

No interaction 2,459 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 2,459 medications checked with no known interaction — see the full Testolone list.

See the full Testolone interactions page
See every supplement checked against Belumosudil Mesylate, ranked by severity
Evidence & sources

Testolone References

The 7 references that drive our Testolone 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.

  1. Joseph JF, Parr MK. Synthetic androgens as designer supplements. Curr Neuropharmacol. 2015;13(1):89-100. PubMed
  2. Warning Letter: Ironmag Labs 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm582464.htm Accessed: November 1, 2017
  3. Warning Letter: Panther Sports Nutrition 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm581630.htm. Accessed: November 1, 2017
  4. Warning Letter: Infantry Labs LLC 10/23/17. FDA Inspections, Compliance, Enforcement, and Criminal Investigations, October 23, 2017. https://www.fda.gov/iceci/enforcementactions/warningletters/2017/ucm582685.htm. Accessed: November 1, 2017
  5. 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
  6. 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
  7. Padappayil RP, Chandini Arjun A, Vivar Acosta J, Ghali W, Mughal MS. Acute myocarditis from the use of selective androgen receptor modulator (SARM) RAD-140 (Testolone). Cureus. 2022;14(1):e21663. PubMed

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 Testolone and Belumosudil Mesylate Together: Common Questions

Is it safe to take Testolone with Belumosudil Mesylate?
We do not list a known interaction between Testolone and Belumosudil Mesylate. 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.
Do Testolone and Belumosudil Mesylate have any of the same side effects?
Yes — our sources link each of them separately to 7 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Testolone and Belumosudil Mesylate at the same time of day?
At least one FDA label for a product containing Belumosudil Mesylate says to take it with food. If you take Testolone on an empty stomach out of habit, keep them separate and take Belumosudil Mesylate with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Belumosudil Mesylate products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Testolone and Belumosudil Mesylate combination checked?
Interactions in our licensed database are recorded against drug classes. Belumosudil Mesylate is filed under 2 classifications, and Testolone has documented interactions with 1 drug class — none of Belumosudil Mesylate'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 Testolone interact with any other medications?
Yes. Testolone has 370 documented drug interactions in our database — Belumosudil Mesylate 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 Belumosudil Mesylate interact with any supplements?
Yes. Belumosudil Mesylate has documented interactions with 138 supplements in our database — Testolone is not one of them. The Belumosudil Mesylate 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

Testolone monograph Uses, safety profile, and every drug interaction in one place Belumosudil drug information The full plain-English guide to this medication Belumosudil Mesylate supplement interactions Every supplement checked against Belumosudil Mesylate, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Belumosudil Mesylate 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.