Interactions on record — worth a quick check against your medications. Based on 1 of 2 ingredients. Check your meds →
Dietary supplement

Lean Mass Ingredients & Drug Interactions

by RS Formulations

Lean Mass label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Lean Mass 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

Lean Mass is a dietary supplement by RS Formulations with 2 active ingredients. 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 ((2S)-3-(4-Cyanophenoxy)-N-[4-Cyano-3-Trifluoromethyl)Phenyl]-2-Hydroxy-2-Methylpropanamide). Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Lean Mass by RS Formulations

Ask about any prescription or over-the-counter medication and we check it for interactions with Lean Mass by RS Formulations — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Lean Mass by RS Formulations

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

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 2 active ingredients.
  • “SARM/Andro Blend” is a proprietary blend — the label gives one combined amount (65 mg) without saying how much of each component you get.

Lean Mass contains 2 active ingredients: ostarine (a SARM being studied for muscle and bone health) and -3-Epihydroxyetioallocholan-17-One. The product also includes gelatin and rice flour as inactive ingredients to form the capsule and provide structure.

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: muscle building and athletic performance.
  • We looked for evidence on: Athletic performance, Sarcopenia, Muscular dystrophy, Cachexia, muscle strength, lean mass gains — and 1 related terms.
  • The closest evidence on file: Ostarine is rated "Insufficient Reliable Evidence To Rate" for Athletic performance (Natural Medicines).
  • Also on file: Ostarine is rated "Insufficient Reliable Evidence To Rate" for Cachexia, Muscular dystrophy, Sarcopenia.

The evidence we hold does not establish effectiveness for any claimed use. Ostarine has insufficient reliable evidence to rate for athletic performance, breast cancer, cachexia (severe muscle wasting), muscular dystrophy, or sarcopenia (age-related muscle loss).

No effectiveness data is on file for the other active ingredient.

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 an unapproved investigational drug with documented safety risks and no FDA approval — that's a core concern here. The most common side effects reported are abdominal pain, loss of appetite, constipation, diarrhea, and nausea.

In clinical trials, some patients (ranging from 4% to 21% depending on dose) showed temporary increases in liver enzymes (ALT), a sign of liver stress; in rare cases, liver damage can occur. A small number of trial participants also showed anemia (low red blood cells) and thrombocytopenia (low platelets).

Ostarine affects hormone pathways, so it must be avoided in pregnancy, and there is no safety data for breastfeeding — avoid it 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, check any hepatotoxic drugs (medications that can damage the liver), drugs that speed liver metabolism like rifampin, probenecid, and any CYP3A4 inhibitors or CYP2C9 substrates you may be on. These interactions are documented at Moderate or Minor severity.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with insufficient evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Lean Mass contains ostarine, an unapproved experimental drug with real safety risks and no proven benefit at established doses. If you take any prescription medication — especially those affecting the liver or metabolized through liver pathways — you need to check it here first.

Talk to your pharmacist or doctor before considering this product; the safety and effectiveness profile does not support routine use.

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

Assessment coverage: 1 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 25, 2020.

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 Lean Mass, straight from the product label.

Brand RS Formulations
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Jan 25, 2020
DSLD ID 211554
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses No Claim
Intended target group(s) Adult (18 - 50 Years)
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 Lean Mass by RS Formulations, 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
60
IngredientAmount% DV
SARM/Andro Blend65 mg--
-3-Epihydroxyetioallocholan-17-One0 NP--
((2S)-3-(4-Cyanophenoxy)-N-[4-Cyano-3-Trifluoromethyl)Phenyl]-2-Hydroxy-2-Methylpropanamide)0 NP--

Other ingredients: Gelatin, Rice Flour

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.
Formulation

Shred the size Strength, no bloat Anabolic stimulator

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Recommended Use: Take one capsule in the morning and one capsule in the evening.

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

See for yourself

Lean Mass by RS Formulations label

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

Lean Mass 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 Lean Mass by RS Formulations

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

SARM/Andro Blend

65 mg per serving

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

Interaction report

Lean Mass by RS Formulations Drug Interactions

Want to check YOUR meds against Lean Mass?

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

((2S)-3-(4-Cyanophenoxy)-N-[4-Cyano-3-Trifluoromethyl)Phenyl]-2-Hydroxy-2-Methylpropanamide) 611

Individual Drug Interactions

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

1 of the 2 ingredients in Lean Mass interact with drugs. Each result below shows which ingredient is responsible. ((2S)-3-(4-Cyanophenoxy)-N-[4-Cyano-3-Trifluoromethyl)Phenyl]-2-Hydroxy-2-Methylpropanamide)

Each ingredient & the kinds of drugs it affects

For each ingredient in Lean Mass 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.

((2S)-3-(4-Cyanophenoxy)-N-[4-Cyano-3-Trifluoromethyl)Phenyl]-2-Hydroxy-2-Methylpropanamide)6 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
((2S)-3-(4-Cyanophenoxy)-N-[4-Cyano-3-Trifluoromethyl)Phenyl]-2-Hydroxy-2-Methylpropanamide) full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Lean Mass, from the product label.

RS Formulations

See all RS Formulations products
Name
Rock Solid Formulations
Pharmacist Counseling Corner

Lean Mass by RS Formulations: Common Questions

Does Lean Mass by RS Formulations interact with any medications?
Yes. Based on its ingredients, Lean Mass 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?
Lean Mass contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
Is ostarine approved by the FDA?
No. Ostarine is an unapproved investigational drug. The FDA has warned that supplements containing SARMs like ostarine carry documented safety risks and are not approved for human use.
What are the most common side effects?
The most common ones reported in trials are abdominal pain, nausea, loss of appetite, constipation, and diarrhea. A notable concern is temporary increases in liver enzymes; in trials, 4% to 21% of users (depending on dose) showed this liver stress marker, and in rare cases liver damage occurred.
Can I take this if I'm pregnant or breastfeeding?
No. 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 — talk with your doctor for personalized advice.
Does this product actually work for muscle gain?
There is insufficient reliable evidence in our data to rate ostarine for athletic performance or any other use. While it's being researched for muscle and bone health, we don't have established proof of benefit at real-world doses.
What is a SARM?
A SARM (selective androgen receptor modulator) is a lab-created compound designed to mimic some effects of testosterone on muscle and bone, but the research and safety profile remain incomplete — these are not approved medicines.

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

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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.

Lean Mass label
Go deeper

The Full Monographs Behind Lean Mass’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

Lean Mass'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

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