Drug & supplement interaction

Ostarine + Montelukast Sodium

Montelukast Sodium brand name: Singulair.

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

Ostarine has a minor interaction with Montelukast Sodium. Theoretically, ostarine might increase levels of drugs metabolized by CYP2C9, although clinical research suggests this is not clinically relevant.

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

Ostarine and Montelukast Sodium

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

Minor

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

Why this applies to Montelukast Sodium

Montelukast Sodium falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Ostarine interacts with.

Theoretically, ostarine might increase levels of drugs metabolized by CYP2C9, although clinical research suggests this is not clinically relevant.
Although in vitro research suggests that ostarine inhibits CYP2C9, more robust clinical research shows that ostarine does not significantly affect CYP2C9.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: your asthma and allergy medicine, montelukast (Singulair), is partly cleared by a liver enzyme called CYP2C9. In test-tube studies, Ostarine looked like it might slow that enzyme down, which in theory could let montelukast build up a little and possibly nudge up side effects like headache, stomach upset, or feeling drowsy.

The reassuring part: better-quality human studies found that Ostarine doesn't meaningfully block CYP2C9, so this is really more of a paper concern than a real-world one. Montelukast isn't a prodrug, so it still works normally either way. My bigger worry isn't this interaction at all, it's Ostarine itself, since it's an unapproved SARM tied to liver injury. Please loop in your pharmacist or doctor before mixing the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Coss CC, Jones A, Dalton JT. Pharmacokinetic drug interactions of the selective androgen receptor modulator GTx-024 (enobosarm) with itraconazole, rifampin, probenecid, celecoxib and rosuvastatin. Invest New Drugs 2016;34(4):458-67. 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 440 moderate, 170 minor known drug interactions in our database — the Montelukast Sodium one above is one of them. If you take anything else, check it against the full list below.

Moderate 440 Minor 170 No known interaction 2,220 (incl. Montelukast Sodium)
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.

From our Q&A

Questions About Ostarine or Montelukast Sodium

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Ostarine or Montelukast Sodium, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Montelukast Sodium

This page covers Ostarine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Montelukast Sodium page lists 81 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), African Wild Potato (moderate), Bacopa (moderate) and Berberine (moderate).

By severity: 1 major · 56 moderate · 24 minor.

From our pharmacist’s overview on the Montelukast Sodium page

“If you rely on montelukast (Singulair) for asthma or allergies, this list deserves genuine attention. The one major-rated concern is activated charcoal, which can soak up the medicine in your gut before it absorbs, leaving you with a weaker dose just when your airways need a steady one.”

Reviewed by 2 · Jul 18, 2026

Open the Montelukast Sodium 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 Montelukast Sodium 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 Montelukast Sodium 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

#1,066 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Montelukast Sodium
Top 5%

#88 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 Montelukast

What Is Montelukast Used For?

Brand name: Singulair

Montelukast is used for the long-term prevention and treatment of asthma in children and adults, and for preventing breathing problems triggered by exercise (exercise-induced bronchoconstriction). It is also used to relieve symptoms of seasonal allergic rhinitis (hay fever) and perennial allergic rhinitis (year-round nasal allergies). The age ranges covered depend on the specific product form — tablets, chewable tablets, and oral granules are each approved for different age groups.

For allergic rhinitis, montelukast should be reserved for people who haven't responded well to other treatments, because its potential mental health risks may outweigh the benefits when nasal allergy symptoms are mild and other options work. It is not a rescue treatment for sudden asthma attacks — always keep a fast-acting inhaler on hand.

See full Montelukast 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
440Moderate
170Minor
2,219No known interaction
440 Moderate 170 Minor 2,219 No interaction
Moderate

440 interactions

Showing 60 of 440 moderate interactions — see all 440 on the Ostarine page.

Minor

170 interactions

Showing 60 of 170 minor interactions — see all 170 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 Montelukast Sodium, 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 Montelukast Sodium supplement interactions › Every supplement checked against Montelukast Sodium, ranked by severity Montelukast 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 Montelukast Sodium Together: Common Questions

Can you take Ostarine with Montelukast Sodium?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Ostarine and Montelukast Sodium interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Montelukast Sodium and Ostarine?

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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.