Drug & supplement interaction

Ostarine + Allopurinol

Allopurinol brand names: Zyloprim, Caplenal, Cosuric, Rimapurinol, Zyloric.

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

Ostarine has a moderate interaction with Allopurinol. Theoretically, concomitant use with hepatotoxic drugs might increase the risk of adverse hepatotoxic effects.

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

Ostarine and Allopurinol

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Allopurinol

Allopurinol falls under HEPATOTOXIC DRUGS — the group Ostarine interacts with.

Theoretically, concomitant use with hepatotoxic drugs might increase the risk of adverse hepatotoxic effects.
Some clinical research shows that ostarine can increase alanine aminotransferase, a marker of liver damage, in some patients. Additionally, the U.S. Food and Drug Administration warns that supplements containing SARMs, such as ostarine, have been associated with reports of liver toxicity and there are at least two reports of drug-induced liver injury attributed to the use of ostarine.
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 concern with pairing these two: both can be tough on your liver. Ostarine (a SARM, not a true supplement) has been tied to liver injury, including rising ALT levels (a blood marker that signals liver stress). Allopurinol, while usually well tolerated, can also occasionally irritate the liver and rarely cause more serious reactions involving rash and liver enzyme changes. Stacking two liver stressors together may add up.

This isn't about one drug changing how the other is broken down. It's simply two things that can each burden the liver at the same time. The evidence here is mostly theoretical, so I don't want to alarm you, but Ostarine isn't FDA-approved and carries real risks. Please loop in your doctor or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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
  2. 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
  3. 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
  4. Dobs AS, Boccia RV, Croot CC, et al. Effects of enobosarm on muscle wasting and physical function in patients with cancer: a double-blind, randomised controlled phase 2 trial. Lancet Oncol 2013;14(4):335-45. PubMed
  5. Dalton JT, Barnette KG, Bohl CE, et al. The selective androgen receptor modulator GTx-024 (enobosarm) improves lean body mass and physical function in healthy elderly men and postmenopausal women: results of a double-blind, placebo-controlled phase II tri
  6. Bedi H, Hammond C, Sanders D, Yang HM, Yoshida EM. Drug-induced liver injury from enobosarm (ostarine), a selective androgen receptor modulator. ACG Case Rep J 2021;8(1):e00518. PubMed
  7. Weinblatt D, Roy S. Drug-Induced Liver Injury Secondary to Enobosarm: A Selective Androgen Receptor Modulator. J Med Cases 2022;13(5):244-248. 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

Ostarine Also Interacts With Other Medications

Ostarine has 439 moderate, 171 minor known drug interactions in our database — the Allopurinol one above is one of them. If you take anything else, check it against the full list below.

Moderate 439 Minor 171 No known interaction 2,220 (incl. Allopurinol)
Taking anything else?

Check Another of Your Medications Against Ostarine

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

Everything else you take

See Every Supplement That Interacts With Allopurinol

This page covers Ostarine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Allopurinol page lists 60 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Siberian Cocklebur (major) and Wine (major).

By severity: 5 major · 45 moderate · 10 minor.

From our pharmacist’s overview on the Allopurinol page

“Allopurinol (Zyloprim) prevents gout attacks by lowering uric acid, and I would give this list real weight, because 5 of the 60 supplements and herbs on file carry a major rating. The largest cluster, 38 ingredients, is products that can stress the liver on their own, and regular beer or wine sits in that major group, since alcohol on…”

Reviewed by 2 · Jul 18, 2026

Open the Allopurinol interaction page

One more smart check

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

We hold 33 real supplement products containing Ostarine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ostarine. Your product may carry other ingredients that interact with Allopurinol too, on top of Ostarine — 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 Ostarine and Allopurinol 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 Ostarine
Steady interest

#1,201 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Allopurinol
Top 25%

#425 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 Ostarine

What is Ostarine?

  • Muscle building
  • Athletic performance
  • Fat loss / body recomposition
  • Bodybuilding cycles

Ostarine (also called MK-2866 or enobosarm) is an experimental, unapproved drug known as a SARM (selective androgen receptor modulator), not a true dietary supplement. It is not approved by the FDA, is banned in sports, and has been linked to liver injury and other serious harms, so it is not recommended for general use.

Read the full Ostarine monograph & all interactions
Medication

About Allopurinol

What Is Allopurinol Used For?

Brand names: Zyloprim, Caplenal, Cosuric, Rimapurinol, Zyloric

Allopurinol tablets (including Zyloprim) are used in adults to treat the signs and symptoms of gout — including gout attacks, tophi (uric acid deposits), joint damage, and kidney problems caused by uric acid. Allopurinol tablets are also used in adults to reduce recurrent calcium oxalate kidney stones when uric acid in the urine is too high, even after lifestyle changes.

For adults and children with leukemia, lymphoma, or solid tumor cancers, allopurinol is used to control uric acid levels that rise during cancer treatment. The injectable forms — Allopurinol sodium for injection and Aloprim — are specifically for patients who cannot take medicine by mouth and are given intravenously (through a vein) in a hospital or clinical setting. Note: allopurinol tablets are not recommended for people who have high uric acid levels but no symptoms.

See full Allopurinol drug information
Keep checking

Other Drugs & Ostarine

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

0Major
439Moderate
171Minor
2,219No known interaction
439 Moderate 171 Minor 2,219 No interaction
Moderate

439 interactions

Showing 60 of 439 moderate interactions — see all 439 on the Ostarine page.

Minor

171 interactions

Showing 60 of 171 minor interactions — see all 171 on the Ostarine page.

No interaction 2,219 drugs checked — show the list

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

Showing the 60 most looked-up of 2,219 medications checked with no known interaction — see the full Ostarine list.

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

Can you take Ostarine with Allopurinol?
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 Ostarine and Allopurinol 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 Allopurinol and Ostarine?

Our pharmacists answer your medication & supplement questions — free.

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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.