RAD-140 (Testolone) Overview
RAD-140, also known by the International Nonproprietary Name vosilasarm and by the development codes RAD140 (Radius Health) and EP0062 (Ellipses Pharma), is a synthetic nonsteroidal selective androgen receptor modulator (SARM). It was originally developed by Radius Health, Inc. and is currently in active clinical development by Ellipses Pharma for androgen receptor-positive (AR+) hormone-sensitive breast cancer.
RAD-140 is among the most extensively studied SARMs in the published literature, characterized as a high-affinity androgen receptor ligand with reported binding K_i of approximately 7 nM. It has been advanced through Phase 1 clinical research investigations (completed in postmenopausal women with breast cancer, 2017–2020) with subsequent clinical development ongoing. The compound is widely cited as a reference SARM in androgen receptor pharmacology, oncology research, and anti-doping analytical chemistry.
RAD-140 is not approved for human or veterinary use and is supplied strictly for laboratory and analytical research purposes.
Mechanism of Action
RAD-140 binds the androgen receptor ligand-binding domain with high affinity and acts as a tissue-differential AR ligand. Published in vitro and preclinical characterizations describe differential transcriptional output across androgen-responsive cell types, with full-agonist activity in cell models representative of muscle- and bone-derived tissues and reduced (partial agonist) activity in prostate-derived reporter models. In AR+/ER+ breast cancer cell lines, RAD-140 has been reported to act as an AR agonist while suppressing ER-mediated signaling and reducing ESR1 mRNA expression, supporting its development as an investigational agent for hormone-sensitive breast cancer.
Reported characterizations include:
- AR binding K_i ≈ 7 nM
- Non-aromatizable nonsteroidal scaffold
- Distinct AR ligand-binding domain conformational pattern relative to testosterone and steroidal androgens
- Published in vitro metabolite profile relevant to analytical and forensic research
- Hepatic metabolism via oxidation and conjugation pathways; renal and biliary excretion in published preclinical PK studies
Chemical Structure & Identification
- Chemical Name: 2-Chloro-4-[[(1R,2S)-1-[5-(4-cyanophenyl)-1,3,4-oxadiazol-2-yl]-2-hydroxypropyl]amino]-3-methylbenzonitrile
- INN: Vosilasarm
- Synonyms: RAD-140; RAD140; Testolone; Vosilasarm; EP0062; Radarol
- Chemical Class: Nonsteroidal benzonitrile / 1,3,4-oxadiazole SARM
- CAS Number: 1182367-47-0
- Molecular Formula: C₂₀H₁₆ClN₅O₂
- Molecular Weight (average): 393.83 g/mol
- Exact Mass (monoisotopic): 393.0993 g/mol
- PubChem CID: 44200882
Structural Description: RAD-140 is a small-molecule, nonsteroidal androgen receptor ligand combining a 2-chloro-3-methylbenzonitrile scaffold with a chiral (1R,2S)-configured 2-hydroxypropyl linker bridging to a 5-(4-cyanophenyl)-1,3,4-oxadiazole heterocycle. The chlorine substituent, the two nitrile groups, the oxadiazole ring, and the chiral hydroxyl are key structural features contributing to AR binding affinity, receptor subtype selectivity, metabolic stability, and the compound’s distinctive analytical signature. Structural identification and molecular data are referenced against PubChem.
Physical and Chemical Properties
- Appearance: White to off-white solid
- Solubility: Soluble in DMSO and similar organic solvents; poorly soluble in water
- Stability: Stable under dry, cool, light-protected storage conditions
- Recommended storage: -20 °C for long-term stability
Research Focus Areas
RAD-140 is commonly referenced in laboratory research involving:
- Androgen receptor binding, competition, and transactivation assays
- SARM structure-activity relationship (SAR) analysis, particularly within the oxadiazole-substituted nonsteroidal AR ligand class
- Nuclear receptor selectivity profiling and AR/ER crosstalk studies (relevant to hormone-sensitive breast cancer research)
- AR ligand-binding domain conformation and coregulator recruitment studies
- Analytical and reference-standard work, including LC-MS/MS method development referenced in anti-doping analytical literature
- In vitro metabolism, ADME, hepatotoxicity, and forensic toxicology research (RAD-140 has been the subject of multiple published case reports addressing hepatic and cardiovascular effects in research literature)
- Comparative SARM evaluation alongside other nonsteroidal AR ligands
Research Background & Regulatory Context
RAD-140 (vosilasarm) is included on the World Anti-Doping Agency (WADA) Prohibited List under the anabolic agents category and is among the most frequently detected SARM analytes in anti-doping testing programs. The U.S. Food and Drug Administration has issued multiple public consumer advisories naming RAD-140 and related SARMs in the context of unapproved bodybuilding and dietary supplement products. The published literature on RAD-140 also includes case reports addressing hepatotoxicity and cardiovascular effects associated with non-medical use. This published regulatory, clinical, and analytical record is part of the scientific literature on the compound and reinforces that RAD-140 is supplied strictly as a research reagent for laboratory and analytical use, not for any therapeutic, performance, dietary supplement, or other consumer application.
Research Use Disclaimer
RAD-140 is intended strictly for laboratory research use only (RUO). Not for human consumption, clinical use, veterinary use, therapeutic application, dietary supplement use, or diagnostic purposes. All handling and use must comply with applicable federal, state, and local laws and institutional laboratory safety standards.
Summary
RAD-140 (vosilasarm, Testolone) is a structurally defined, well-characterized nonsteroidal selective androgen receptor modulator with active clinical development through Ellipses Pharma for hormone-sensitive breast cancer. Its benzonitrile-oxadiazole scaffold, well-defined binding profile, INN designation, and ongoing pharmaceutical development make it a widely used reference compound in controlled laboratory studies of androgen receptor signaling, oncology research, and anti-doping analytical method development.
| CAS Number | 1182367-47-0 |
| Other Names | Testolone, RAD140, RAD 140, Vosilasarm, 4O87Q44KNC, CHEMBL1672635, D09ZLZ |
| IUPAC Name | 2-chloro-4-[[(1R,2S)-1-[5-(4-cyanophenyl)-1,3,4-oxadiazol-2-yl]-2-hydroxypropyl]amino]-3-methylbenzonitrile |
| Molecular Formula | C₂₀H₁₆ClN₅O₂ |
| Molecular Weight | 393.8 |
| Dry-Fill Capsule Concentration | 10mg |
| Liquid Concentration And Solution | 30mg/ml PEG400, DMSO |
| Aliquot Concentration And Solution | 50mg/ml (PEG400, Propylene Glycol, Benzyl benzoate, Benzyl Alcohol) |
