Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Ostarine Ingredients & Drug Interactions

by Swole Labs

Ostarine label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Ostarine against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Ostarine is a dietary supplement by Swole Labs with 1 active ingredient. Its ingredients are commonly taken for muscle building, athletic performance, fat loss / body recomposition.Based on those ingredients, 611 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Ostarine-MK 2866. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Ostarine by Swole Labs

Ask about any prescription or over-the-counter medication and we check it for interactions with Ostarine by Swole Labs — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Ostarine by Swole Labs

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Ostarine-MK 2866 is the single active ingredient in this product. It's an investigational selective androgen receptor modulator (SARM) — a compound designed to affect hormone pathways in your body, though it remains unapproved by the FDA.

The capsules also contain rice flour, gelatin, and magnesium stearate as inactive ingredients.

Does it work?

Insufficient evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Insufficient

There isn't enough reliable clinical evidence to rate this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: performance training and physique enhancement.
  • We looked for evidence on: Athletic performance, Muscle strength, Body composition, Lean mass.
  • The closest evidence on file: Ostarine is rated "Insufficient Reliable Evidence To Rate" for Athletic performance (Natural Medicines).

We hold insufficient reliable evidence to rate ostarine for any of its claimed uses — athletic performance, breast cancer, cachexia (severe muscle wasting), muscular dystrophy, and sarcopenia (age-related muscle loss). The facts we have don't establish whether it actually works for these purposes.

The evidence, ingredient by ingredient Ostarine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Ostarine is rated possibly unsafe to take by mouth and is an unapproved investigational drug with documented safety risks. Common side effects include abdominal pain, loss of appetite, constipation, diarrhea, and nausea.

A notable concern is transient elevation of liver enzymes — in one trial, about 7% of patients on the 3 mg dose and over 20% on that same dose in another study showed increases in alanine aminotransferase (a liver damage marker), though levels usually resolved. Rare but serious liver damage has been reported.

In cancer patients, anemia and low platelet counts occurred more often with ostarine than placebo, though rates were similar between groups. Ostarine affects hormone pathways and must be avoided during pregnancy.

There is no safety data for breastfeeding, so it should be avoided then as well.

Side effects, ingredient by ingredient Ostarine

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Ostarine.
  • The most serious interaction on file is rated Moderate.
  • For scale: 612 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, double-check with your pharmacist if you take any hepatotoxic (liver-damaging) medications, CYP3A4 inducers like rifampin, probenecid for gout, or CYP3A4 inhibitors — all carry moderate-severity interaction risks. This is a conversation to have before you start, not after.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with insufficient evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Ostarine is an unapproved drug with real safety risks and no established evidence it works for its claimed uses. Because it interacts with hundreds of medications and can affect your liver, it's not something to start without a serious conversation with your doctor or pharmacist about your specific health and medications.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Dec 22, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Ostarine, straight from the product label.

Brand Swole Labs
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Dec 22, 2019
DSLD ID 210120
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Ostarine by Swole Labs, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
90
IngredientAmount% DV
Ostarine-MK 286620 mg--

Other ingredients: Rice Flour, Gelatin, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Performance training usage: This product is intended for use as an addition to any workout regimen. As a physique enhancing agent take 1 capsule 1 to 2 times daily. Do not consume more than 2 capsules in a 24 hour period. Do not under any circumstances exceed 4 weeks of use without at least a 30 day break. During the 30 day break period we strongly suggest the use of a proper post cycle therapy product. Cycle Resurrection has been specifically formulated to meet those needs.

Precautions

Warning: Keep out of reach of children.

Do not use if pregnant or nursing.

To report any adverse event call 1-800-332-1088. Consult you doctor prior to use if you have or are at risk for prostate disease, heart disease, or any other general medical condition.

Consult your doctor prior to use if you are taking any other medications.

Do not exceed suggested dosage. Discontinue use immediately if you experience rapid heart beat, dizziness, vomiting, or other similar symptoms. Side effects may include acne, hair loss, or increased aggressiveness. All persons are advised to consult with their doctor or other medical authority before use of this or any other dietary supplements. Caution: Athletes or other persons who are subject to testing for performance enhancing drugs may test positive when using dietary supplements. All persons are advised to consult their drug testing organization prior to use of this or any other dietary supplement.

May not be suitable for persons under the age of 18 years old.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Formula

MK-2866

Formulation

Joint Healing Ability Decreases Body Fat Increase Lean Mass Maximize Strength

General Statements

When big isn't good enough!! Platinum Series

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Ostarine by Swole Labs label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Ostarine label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Ostarine by Swole Labs

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container90 Amounts shown are per serving.

Ostarine-MK 2866

Interacts with
611 drugs
20 mg per serving

Ostarine (also called MK-2866 or enobosarm) is an experimental, unapproved drug known as a SARM (selective androgen receptor modulator), not a true di...

Ostarine-MK 2866 monograph & interactions

Other (inactive) ingredients: Rice Flour, Gelatin, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Ostarine by Swole Labs Drug Interactions

Want to check YOUR meds against Ostarine?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
611Drugs
440 Moderate 171 Minor

Ingredients driving the most interactions

Ostarine-MK 2866 611

Individual Drug Interactions

The ingredients in Ostarine interact with 611 drugs. Click any drug to see the details.

1 of the 1 ingredient in Ostarine interact with drugs. Each result below shows which ingredient is responsible. Ostarine-MK 2866

Each ingredient & the kinds of drugs it affects

For each ingredient in Ostarine with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Ostarine-MK 28666 drug types · 611 drugs

Cytochrome P450 3A4 (Cyp3A4) Inducers

Theoretically, concomitant use of ostarine with CYP3A4 inducers could decrease the clinical effects of ostarine.
Ostarine is partially metabolized by CYP3A4. Clinical research shows that taking rifampin, a potent inducer of CYP3A4, reduces the maximum plasma concentration of ostarine by 23% and the area under the curve by 43%.

Likelihood Possible Evidence B
Hepatotoxic Drugs

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.

Likelihood Possible Evidence D
Probenecid (Benemid)

Theoretically, concomitant use of ostarine with probenecid could increase the effects and adverse effects of ostarine.
Clinical research shows that probenecid increases ostarine levels and slows the clearance of ostarine, likely via inhibition of UDP-glucuronosyltransferase (UGT). Ostarine is partially metabolized by UGT.

Likelihood Possible Evidence B
Rifampin (Rifadin)

Theoretically, concomitant use of ostarine with rifampin could decrease the clinical effects of ostarine.
Clinical research shows that taking rifampin with ostarine reduces the maximum plasma concentration of ostarine by 23% and the area under the curve by 43%. Ostarine is partially metabolized by cytochrome P450 3A4 (CYP3A4), and rifampin is a potent CYP3A4 inducer.

Likelihood Possible Evidence B
Cytochrome P450 2C9 (Cyp2C9) Substrates

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.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Inhibitors

Theoretically, concomitant use of ostarine with CYP3A4 inhibitors could increase the effects and adverse effects of ostarine, although this is unlikely to be clinically significant.
Ostarine is partially metabolized by CYP3A4. However, clinical research shows that taking itraconazole, a potent inhibitor of CYP3A4, had minimal effects on the levels of ostarine in the body.

Likelihood Unlikely Evidence B
Ostarine-MK 2866 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Ostarine, from the product label.

Swole Labs

See all Swole Labs products
Name
Swole Labs
Web Address
Swole-Labs.com
Pharmacist Counseling Corner

Ostarine by Swole Labs: Common Questions

Does Ostarine by Swole Labs interact with any medications?
Yes. Based on its ingredients, Ostarine has a known interaction with 611 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Ostarine contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What is ostarine, exactly?
It's an investigational selective androgen receptor modulator — a compound that affects hormone pathways in your body. It's not approved by the FDA, and the facts make clear it carries documented safety risks.
Does ostarine actually build muscle or improve athletic performance?
We hold insufficient reliable evidence to say whether it works for athletic performance, muscle growth, or any of its other claimed uses. The data we have doesn't establish that it does.
What are the most common side effects?
Abdominal pain, loss of appetite, constipation, diarrhea, and nausea are the most common. A key concern is that it can raise liver enzymes — in clinical trials, 7% to over 20% of patients at higher doses showed increases in a liver damage marker.
Is it safe to take if I'm pregnant or breastfeeding?
No. The safety data advises against ostarine during pregnancy because it affects hormone pathways. There's no safety data for breastfeeding, so it should be avoided then too. Talk with your doctor about your specific situation.
How do I know if this interacts with my medications?
Ostarine interacts with a large number of drugs — over 590 individual medications across several categories. Use the medication checker on this page with your exact drug names and dosages, and definitely talk with your pharmacist before starting.

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

Not sure if Ostarine is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Ostarine label
Go deeper

The Full Monographs Behind Ostarine’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Ostarine

Interacts with 611 drugs

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...

Read the full Ostarine monograph →
Sources

Sources & How We Checked

Ostarine's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 10 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Ostarine 10 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. 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
  7. FDA. FDA Warns against using SARMs in body building products. October 2017. Available at: https://www.fda.gov/newsevents/newsroom/fdainbrief/ucm583021.htm.
  8. 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
  9. Kintz P, Gheddar L, Paradis C, et al. Peroxisome Proliferator-Activated Receptor Delta Agonist (PPAR- d) and Selective Androgen Receptor Modulator (SARM) Abuse: Clinical, Analytical and Biological Data in a Case Involving a Poisonous Combination of GW1516
  10. 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

See these in context on the Ostarine monograph →

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
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team