Drug & supplement interaction

Testolone + Mepolizumab

Mepolizumab brand name: Nucala.

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 Testolone and Mepolizumab 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 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 Mepolizumab

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 Mepolizumab 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 Mepolizumab and Testolone? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

Keep it in perspective

Testolone Does Interact With Other Medications

Testolone has 370 moderate known drug interactions in our database — Mepolizumab 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. Mepolizumab)

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 Mepolizumab 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.

Itching / Diarrhea 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

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

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

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

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

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
Mepolizumab

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

Reported for Testolone but not commonly for Mepolizumab: liver problems, a heart attack, shortness of breath and reduced appetite.

Effects for Mepolizumab come from the ADVERSE REACTIONS section of its FDA label; effects for Testolone come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 49,399 voluntary FDA FAERS reports for Mepolizumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. 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

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 Mepolizumab, 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 Mepolizumab 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

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

29 days ago today

Medication Mepolizumab

Steady interest

#2,664 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 Mepolizumab 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 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 Mepolizumab Injection

What Is Mepolizumab Injection Used For?

Brand name: Nucala

Nucala is used as an add-on maintenance treatment — meaning it works alongside other medications, not instead of them. It is approved for severe asthma (in patients 6 years and older with high eosinophil levels), chronic rhinosinusitis with nasal polyps (CRSwNP) in adults 18 and older whose symptoms aren't controlled by nasal corticosteroids alone, and COPD in adults with an eosinophilic phenotype whose disease isn't adequately controlled.

Nucala is also approved to treat eosinophilic granulomatosis with polyangiitis (EGPA), a rare form of blood vessel inflammation, and hypereosinophilic syndrome (HES), a condition involving dangerously elevated eosinophil counts, in adults and adolescents 12 and older. It is not meant to relieve sudden asthma attacks or acute COPD flares.

Most-Reported Side Effects for Mepolizumab

From FAERS, the FDA’s public side-effect reporting system (49,399 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Asthma 12,767 reports

Dyspnea 10,576 reports

Wheezing 7,131 reports

Cough 5,100 reports

Therapeutic product effect incomplete 5,051 reports

See full Mepolizumab 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

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 Mepolizumab, 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.

Joseph JF, Parr MK. Synthetic androgens as designer supplements. Curr Neuropharmacol. 2015;13(1):89-100. PubMed
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
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
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
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
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
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 Mepolizumab Together: Common Questions

Is it safe to take Testolone with Mepolizumab?

We do not list a known interaction between Testolone and Mepolizumab. 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 Mepolizumab have any of the same side effects?

Yes — our sources link each of them separately to 2 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.

Does Testolone interact with any other medications?

Yes. Testolone has 370 documented drug interactions in our database — Mepolizumab is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

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 Mepolizumab Injection drug information The full plain-English guide to this medication Mepolizumab supplement interactions Every supplement checked against Mepolizumab, 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 Mepolizumab 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.