For laboratory research use only. Not for human consumption. All compounds referenced in this article are sold by Explicit SARMs solely as reference materials for in-vitro and animal research by qualified professionals. Nothing here is medical advice, and no statement has been evaluated by the FDA. These materials are not intended to diagnose, treat, cure or prevent any disease.
RAD-140, often listed under the trade-style name Testolone, is one of the most frequently referenced nonsteroidal selective androgen receptor modulators (SARMs) in the preclinical literature. It was designed to activate the androgen receptor (AR) in some tissues while producing weaker activity in others, a property known as tissue selectivity. This review summarizes what the published literature actually reports about RAD-140: how it interacts with the androgen receptor, how its research history developed, what the animal and early clinical data show, and what laboratories should consider when sourcing, storing and documenting the compound.
Explicit SARMs supplies RAD-140 Testolone Capsules and RAD-140 Liquid strictly as reference material for in-vitro and animal research.
What Is RAD-140?
RAD-140 is a synthetic, nonsteroidal ligand of the androgen receptor. Its chemical scaffold is unrelated to testosterone or other steroid hormones, which is why it is grouped with other nonsteroidal SARMs such as Ostarine (MK-2866) and LGD-4033. The compound was developed by Radius Health, and the code name “RAD140” reflects that origin. It has since been assigned the international nonproprietary name vosilasarm.
Key identifiers commonly used in laboratory records:
- Common names: RAD-140, RAD140, Testolone, vosilasarm
- Class: nonsteroidal selective androgen receptor modulator
- Primary target: androgen receptor (nuclear hormone receptor family)
- Regulatory status: not approved by the FDA or any other regulator for any indication
Mechanism of Action
The androgen receptor is a ligand-activated transcription factor. When a ligand binds the receptor’s ligand-binding domain, the receptor changes shape, moves into the nucleus, binds androgen response elements on DNA and recruits coactivator or corepressor proteins. Which coregulators are recruited depends partly on the shape the ligand induces and partly on which coregulators are present in a given cell type.
This is the working explanation for tissue selectivity. A steroidal androgen such as testosterone is also converted by 5-alpha reductase into dihydrotestosterone (DHT) in tissues like the prostate, and by aromatase into estradiol. Nonsteroidal SARMs such as RAD-140 are not substrates for either enzyme, so they do not produce those amplified or estrogenic metabolites. Combined with ligand-specific coregulator recruitment, that is the main reason researchers observe different activity in skeletal muscle and bone compared with androgen-dependent reproductive tissues in rodent models. [6]
In the original characterization by Miller and colleagues, RAD-140 bound the androgen receptor with high affinity and showed good selectivity over other steroid receptors, including the progesterone and glucocorticoid receptors. [1]
Research History
RAD-140 was first described in detail in a 2011 paper in ACS Medicinal Chemistry Letters, which reported its design, synthesis and preclinical profile. [1] In castrated rat models, the compound stimulated the levator ani muscle at exposures that produced comparatively limited stimulation of the prostate and seminal vesicles, the classic assay used to separate anabolic from androgenic activity. The same work included pharmacokinetic data in animals.
Research interest then broadened in two directions:
- Neuroscience. A 2014 study in Endocrinology reported that RAD-140 protected cultured hippocampal neurons against apoptotic insults and reduced neuron loss in kainate-lesioned male rats, an effect linked to MAPK signaling. [2]
- Oncology. Because AR activation can oppose estrogen-receptor signaling in some breast tumors, RAD-140 was studied in AR-positive, ER-positive breast cancer models. A 2017 paper in Clinical Cancer Research reported that RAD-140 inhibited tumor growth in xenograft models and suppressed expression of ESR1, the gene encoding estrogen receptor alpha. [3]
What Published Studies Report
Preclinical data
Across the rodent and primate work published to date, the recurring findings are high AR affinity, good bioavailability without injection, and a tissue-selective profile in the classic Hershberger-style assays. [1] The neuroprotection and breast cancer xenograft work show that the compound’s AR activity has effects well beyond skeletal muscle and bone. [2][3]
Early clinical research
The only registered interventional trial is a phase 1, first-in-human study in postmenopausal women with ER-positive, HER2-negative metastatic breast cancer (NCT03088527). Results were published in Clinical Breast Cancer in 2022. [4] Investigators reported evidence of AR engagement and some signs of anti-tumor activity, but elevated liver enzymes were among the most common adverse events. Hepatic findings are therefore a central part of the published safety picture.
Adverse event reports
Separate from the trial, the medical literature contains case reports of drug-induced liver injury associated with unregulated products labeled as containing RAD-140, sometimes in combination with LGD-4033. [5] These reports involve products of unknown composition and cannot establish causation on their own, but they are consistent with the hepatic signal seen in the controlled study.
Research Considerations
Laboratories designing work with RAD-140 commonly account for the following:
- Endocrine feedback. In animal models, systemic AR agonists suppress the hypothalamic-pituitary-gonadal axis. Study designs that measure LH, FSH or endogenous testosterone need appropriate vehicle controls and time points.
- Hepatic endpoints. Given the clinical and case-report data, liver enzyme panels and histology are relevant endpoints in animal protocols.
- Tissue selectivity is relative. Selectivity in rodent assays is a ratio, not an absolute; reproductive tissues still respond at higher exposures.
- Assay context. Coregulator expression differs among cell lines, so in-vitro AR reporter results may not translate across cell types.
- Reference standards. Run an authenticated reference standard alongside study material when developing HPLC or LC-MS methods.
How RAD-140 Compares With Other SARMs
RAD-140 is often compared with Ostarine and LGD-4033, and the comparison is mostly a question of what kind of evidence exists for each. Ostarine has the largest clinical dataset, including phase 3 trials. LGD-4033 has a phase 1 study in healthy volunteers and a phase 2 hip fracture study. RAD-140 has strong preclinical characterization and a single phase 1 oncology trial in postmenopausal women with breast cancer. [1][4]
Chemically, RAD-140 does not share the aryl-propionamide scaffold of Ostarine, S4 and S-23, or the pyrrolidinyl-benzonitrile scaffold of LGD-4033. Different scaffolds can stabilize different receptor conformations, which is one reason SARMs with similar binding affinity can behave differently in tissue assays.
RAD-140 also has a published research footprint in two areas most SARMs lack: neuroprotection models and AR-positive, ER-positive breast cancer biology. [2][3] For laboratories working on androgen receptor signaling in the nervous system or in hormone-dependent tumors, those papers are the most relevant starting points.
WADA Status
RAD140 is named explicitly in section S1.2 (Other Anabolic Agents) of the World Anti-Doping Agency Prohibited List and is prohibited at all times. [8] Anti-doping laboratories have published validated methods to detect SARMs and their metabolites. [7]
Storage, Purity and COA
RAD-140 is supplied as a solid in capsules and as a solution in the liquid format. General handling practices for both:
- Store sealed, away from light and moisture, at controlled room temperature or cooler. Avoid repeated temperature swings.
- Keep liquid material tightly capped to limit solvent evaporation, which would change concentration over time.
- Record lot numbers in lab notebooks so results can be traced to a specific batch.
- Review the Certificate of Analysis (COA) for the specific lot. A useful COA identifies the compound, reports purity by HPLC, confirms identity by mass spectrometry, and lists the lot number and test date.
For lot documentation, contact us through the contact page.
Related Research Compounds
- LGD-4033 Ligandrol Capsules, a nonsteroidal SARM with a published phase 1 dataset
- Ostarine MK-2866 Capsules, the most clinically studied SARM
- S23 Capsules, a high-affinity research SARM
- Overview of the class: SARMs vs Traditional Research Compounds and the full SARMs collection
Frequently Asked Questions
Is RAD-140 a steroid?
No. RAD-140 is nonsteroidal. It binds the androgen receptor, but its chemical structure is not based on the steroid nucleus, and it is not converted to DHT or estradiol.
Is RAD-140 approved for any medical use?
No. RAD-140 has not been approved by the FDA or any other regulator. Its only registered clinical study is an early-phase oncology trial.
What is vosilasarm?
Vosilasarm is the international nonproprietary name assigned to RAD140. Both names refer to the same molecule.
What does the safety literature show?
The phase 1 trial reported elevated liver enzymes among the most common adverse events, and separate case reports describe liver injury associated with unregulated products labeled as RAD-140. [4][5]
Is RAD-140 prohibited in sport?
Yes. It is listed by name in WADA section S1.2 and is prohibited both in and out of competition. [8]
What is the difference between the capsule and liquid formats?
The active compound is the same. Capsules provide pre-measured solid material, while the liquid is a solution that some laboratories prefer for preparing dilutions. The choice depends on the protocol.
References
- Miller CP, et al. Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140. ACS Med Chem Lett. 2011. PubMed 24900290
- Jayaraman A, et al. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats. Endocrinology. 2014. PubMed 24428527
- Yu Z, et al. Selective Androgen Receptor Modulator RAD140 Inhibits the Growth of Androgen/Estrogen Receptor-Positive Breast Cancer Models with a Distinct Mechanism of Action. Clin Cancer Res. 2017. PubMed 28974548
- LoRusso P, et al. A First-in-Human Phase 1 Study of a Novel Selective Androgen Receptor Modulator (SARM), RAD140, in ER+/HER2- Metastatic Breast Cancer. Clin Breast Cancer. 2022. PubMed 34565686; trial record NCT03088527
- Barbara M, et al. Drug-Induced Liver Injury Associated With Alpha Bolic (RAD-140) and Alpha Elite (RAD-140 and LGD-4033). ACG Case Rep J. 2020. PubMed 33062783
- Narayanan R, et al. Development of selective androgen receptor modulators (SARMs). Mol Cell Endocrinol. 2018. PubMed 28624515
- Thevis M, Schanzer W. Detection of SARMs in doping control analysis. Mol Cell Endocrinol. 2018. PubMed 28137616
- World Anti-Doping Agency. 2026 Prohibited List. wada-ama.org
For laboratory research use only. Not for human consumption. All compounds referenced in this article are sold by Explicit SARMs solely as reference materials for in-vitro and animal research by qualified professionals. Nothing here is medical advice, and no statement has been evaluated by the FDA. These materials are not intended to diagnose, treat, cure or prevent any disease.