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width:21px;height:21px;background:var(–c-forest);color:var(–c-lime);border-radius:6px; font-size:.72rem;font-weight:800;display:flex;align-items:center;justify-content:center} /* ———- DISCLAIMER ———- */ .stl-note{margin-top:8px;padding:16px 18px;border-left:4px solid var(–c-green);background:#f2f7f4; border-radius:0 10px 10px 0;font-size:.85rem;color:var(–c-mut)} .stl-note b{color:var(–c-logo)} /* ———- NO-JS FALLBACK ———- */ .stl-pdp–nojs .stl-spec__tabs{display:none} .stl-pdp–nojs .stl-spec__panel[hidden]{display:block} .stl-pdp–nojs .stl-spec__panel + .stl-spec__panel{border-top:1px solid var(–c-line)} @media (max-width:760px){ .stl-grid4{grid-template-columns:1fr 1fr} .stl-stats{grid-template-columns:1fr 1fr} .stl-feat,.stl-reg__grid{grid-template-columns:1fr} .stl-spec__table th{width:46%} } @media (max-width:440px){.stl-grid4{grid-template-columns:1fr}} @media (prefers-reduced-motion:reduce){.stl-pdp *{transition:none!important}} /* ———- READABILITY ———- */ .stl-pdp{font-size:16px} .stl-pdp p,.stl-pdp li,.stl-pdp td,.stl-pdp th,.stl-pdp .stl-spec__table{font-size:16px;line-height:1.65} .stl-pdp .stl-chip span,.stl-pdp .stl-sub,.stl-pdp .stl-stat span,.stl-pdp .stl-feat p,.stl-pdp .stl-reg__card p,.stl-pdp .stl-trust__row p,.stl-pdp .stl-refs li,.stl-pdp .stl-note,.stl-pdp .stl-copy__btn,.stl-pdp .stl-btn,.stl-pdp .stl-spec__tab{font-size:16px} .stl-pdp h3{font-size:1.4rem} .stl-pdp h2{font-size:clamp(2rem,3vw,2.5rem)} /* ———- FONT FLOOR: nothing below 14px, desktop + mobile ———- */ .stl-pdp .eyebrow,.stl-pdp .eyebrow–lime{font-size:14px} .stl-pdp .stl-pill{font-size:14px} .stl-pdp .stl-coa figcaption{font-size:14px} .stl-pdp .stl-refs li::before{font-size:14px} .stl-pdp .stl-spec__table sub{font-size:14px} .stl-pdp .stl-spec__table caption{font-size:18px} Why this batch Key highlights Precise measured solutionSuspended in USP-grade solvent for consistent solubility and accurate measurement across research applications. Topical research formulation30 mL bottle at 50 mg/mL with a spray applicator dispensing approximately 1/6 mL per pump. Independently verifiedEvery batch is HPLC-tested by an accredited US third-party lab for purity and identity. Research use onlySupplied exclusively for laboratory investigation and development. Technical data Product specifications Specifications Lab Reports Storage & Handling Liquid RU-58841 — 50 mg/mL (Topical) Compound Class Non-steroidal Anti-androgen (NSAA) · Androgen Receptor Antagonist Concentration 50 mg/mL Composition USP-grade solvent base, RU-58841 (≥99% purity) CAS Number 154992-24-2Copy Chemical Formula C17H18F3N3O3Copy Molar Mass 369.3 g/mol Synonyms RU-58841, PSK-3841, HMR-3841 Format Topical liquid, spray applicator (~1/6 mL per pump) Volume 30 mL per bottle (1,500 mg total) Verified Purity Batch-tested to 99.31% (HPLC) Terms For laboratory research use only. Not for human or animal consumption. View certificates of analysis Independently verified99.31% pure Every batch is analyzed by an accredited US third-party laboratory before it ships. Accredited testing partner Purity and identity confirmed by MZ Biolabs (Tucson, AZ), a US DEA-licensed analytical facility, via HPLC purity analysis and mass-spectrometry identity confirmation under GLP standards. Published certificates of analysis Our third-party certificates of analysis are published on our website — no login required. Under 5% concentration variance Each bottle is formulated and verified for consistent label-to-bottle accuracy across studies. Most recent batch certificate of analysis for RU-58841, issued by MZ Biolabs (Tucson, AZ). Tap to view full size. See all certificates of analysis Storage & handling Built to preserve compound integrity throughout your research timeline. Storage: Keep in a cool, dry place away from direct sunlight to maximize shelf life. UV-resistant glass bottle with spray applicator dispensing approximately 1/6 mL per pump for measured application. Tamper-proof seal to ensure integrity in transit. Handle as a laboratory chemical using appropriate personal protective equipment and standard lab practices. Sourcing & quality Why source RU-58841 from Sports Technology Labs Quality control across the research-compound industry is inconsistent, which makes third-party verification essential. A 2017 analysis published in JAMA examined 44 products marketed online as SARMs and reported wide gaps between labels and contents. 52%contained the labeled compound 39%contained an unapproved drug 25%contained an unlabeled substance 9%contained no active ingredient Source: Van Wagoner et al., JAMA, 2017 (ref. 2). Third-party tested & certified Verified by MZ Biolabs (Tucson, AZ), an accredited US laboratory, via HPLC and mass spectrometry. USP-grade solvent base Suspended in the highest grade carrier and bottled in America. Glass bottles Bottled in glass to prevent leaching of plasticizers such as BPA. 60-day money-back guarantee Transparent business, standard payment methods, no misrepresentation. Research context What is RU-58841? RU-58841 is a non-steroidal anti-androgen (NSAA) that acts as an antagonist of the androgen receptor. Mechanistically, it binds the androgen receptor and blocks androgen binding without reducing circulating androgen levels. It was first developed by French researchers (Roussel Uclaf) and is formulated for topical application in research contexts (ref. 1). RU-58841 remains an experimental research chemical and is supplied strictly for laboratory research. Sports Technology Labs makes no claims regarding its effects, and nothing in this listing should be interpreted as describing outcomes in humans or animals. Regulatory & compliance status Important regulatory information Not approved for human use RU-58841 is an investigational compound. It is not approved by the FDA, cannot be prescribed or sold at pharmacies, and is not a dietary supplement, drug, or food. Marketing it for human use is unlawful. For laboratory research only This preparation is intended for laboratory research and development by qualified professionals, not for introduction into humans or animals by any route. Legal status for research In the United States, RU-58841 is not a controlled substance and may be legally purchased and possessed for laboratory research use. Our position Sports Technology Labs are chemical suppliers, not medical providers. We do not condone or encourage consumer use of research compounds. Citations Scientific references National Center for Biotechnology Information. PubChem Compound Summary for RU-58841 (CAS 154992-24-2): molecular formula, molecular weight, and classification. PubChem, National Library of Medicine. Van Wagoner RM, et al. Chemical composition and labeling of substances marketed as SARMs and sold via the internet. JAMA. 2017;318(20):2004–2010. Research use only. All products on this website are intended exclusively for laboratory research and development. They are not for human or animal consumption. These statements have not been evaluated by the U.S. Food and Drug Administration, and these products are not intended to diagnose, treat, cure, or prevent any disease. {“@context”:”https://schema.org”,”@type”:”ChemicalSubstance”,”name”:”RU-58841″,”alternateName”:[“RU-58841″,”PSK-3841″,”HMR-3841″],”identifier”:[{“@type”:”PropertyValue”,”propertyID”:”CAS”,”value”:”154992-24-2″}],”molecularFormula”:”C17H18F3N3O3″,”molecularWeight”:”369.3 g/mol”,”description”:”Liquid RU-58841, 50 mg/mL topical, a non-steroidal anti-androgen (androgen receptor antagonist) supplied for laboratory research use only. 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