RAD-140 (Testolone) is a selective androgen receptor modulator (SARM) that has drawn significant attention across preclinical research circles. Studies in animal models suggest it interacts selectively with androgen receptors in muscle and bone tissue. Research on RAD-140 is still evolving, and findings remain largely preclinical. Plus, no human safety profile has been established. RAD-140 Capsules formulations are widely used in laboratory settings for consistent, measurable dosing in cell-based and animal studies.
Here is a fact that surprises many in the research community: RAD-140 was originally developed not for performance-related investigation, but as a potential research tool in the context of hormone-sensitive tissue studies. A compound designed to interact with androgen receptors, without triggering the full hormonal cascade of traditional anabolic compounds, was the original premise. And yet, over the past decade, RAD-140 has become one of the most actively studied SARMs in preclinical science.
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What is driving that interest? It comes down to selectivity. Researchers exploring androgen receptor modulation have long sought compounds that can isolate specific receptor populations in tissue models, and RAD-140’s molecular design positions it as a useful tool for exactly that kind of work. The capsule form, in particular, has made it easier to standardize lab protocols and maintain consistent delivery across test models.
This article provides a molecular overview of what published preclinical research has explored regarding RAD-140 capsules, including receptor binding behavior, key study observations, risk considerations, and where research institutions source verified material.
Disclaimer: RAD-140 (Testolone) is a research compound not approved by the U.S. Food and Drug Administration (FDA) for human or veterinary use. It is not a dietary supplement or consumer product, and it is not intended to diagnose, treat, cure, or prevent any disease. This RAD-140 Capsules content is for informational purposes only. Always consult a licensed medical professional before making any health-related decisions.
What Is RAD-140, and Why Are Researchers Interested in It?
RAD-140, also known by its systematic name Testolone, is a non-steroidal SARM first synthesized by Radius Health in the early 2010s. Its molecular formula is C₂₀H₁₆ClN₅O₂, with a molecular weight of approximately 393.83 g/mol.
Unlike steroidal androgens, RAD-140 was engineered to bind androgen receptors with high affinity while maintaining a degree of tissue selectivity – a property that has made it a useful research compound in studies investigating androgen receptor (AR) signaling pathways.
Key structural characteristics that researchers note:
- Non-steroidal backbone – distinct from testosterone derivatives in molecular geometry
- High binding affinity to the AR ligand-binding domain (Ki ~7 nM) [Miller et al., 2010/2011]
- Designed to exhibit differential activity in muscle vs. reproductive organ tissue in preclinical models
- Orally bioavailable structure – making capsule formulations well-suited for in vivo research protocols
A 2010 preclinical study published in ACS Medicinal Chemistry Letters by Miller et al. titled Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140 characterized RAD-140’s binding profile and noted selective activity patterns compared to testosterone in rodent models – one of the earliest peer-reviewed descriptions of the compound’s molecular behavior.
How Does RAD-140 Interact With Androgen Receptors at the Molecular Level?
RAD-140 binds the androgen receptor’s ligand-binding domain (LBD) with high affinity. Once bound, it initiates a conformational change in the receptor folding helix 12 into a position that facilitates co-activator recruitment.
This is the same general pathway activated by endogenous androgens like testosterone and DHT. What distinguishes RAD-140 in preclinical models is how this activation manifests differently across tissue types. This is a property researchers refer to as tissue-selective AR modulation.
What Is Selective Androgen Receptor Modulation?
The selectivity concept in SARMs research is built around the idea that AR activity is mediated not only by ligand binding but also by:
- The specific co-regulator proteins expressed in each tissue
- Post-translational receptor modifications
- Local intracellular signaling environments
Because different tissues carry different co-regulatory landscapes, the same AR ligand can produce partial agonist activity in one tissue while acting as a full agonist or even antagonist in another. RAD-140’s molecular profile has made it a frequently referenced compound in studies exploring this mechanism.
Anabolic-to-Androgenic Ratio in Preclinical Models
In the original Miller et al. (2010) preclinical characterization, RAD-140 capsules demonstrated an anabolic-to-androgenic ratio of approximately 90:1 compared to testosterone propionate in rodent models, with notable differential activity between the levator ani muscle and the prostate. These observations have made it a common reference compound in AR tissue-selectivity research.
What Has Preclinical Research Explored Regarding RAD-140?
The following observations come from peer-reviewed preclinical literature. These findings are from animal models and in vitro settings. These do not constitute clinical evidence of safety or efficacy in humans.
Muscle and Bone Tissue Studies
The Miller et al. (2010) study in ACS Medicinal Chemistry Letters remains the foundational reference for RAD-140’s anabolic tissue activity in preclinical models. Researchers observed increased lean mass markers in castrated rodent models administered RAD-140, with comparatively lower androgenic signaling at reproductive organs than testosterone controls.
Bone density marker studies in rodent models have also referenced RAD-140 as a comparison compound in AR modulation protocols, though this remains a secondary area of investigation.
Neuroprotective Signaling Pathways
One of the more unexpected areas of RAD-140 preclinical investigation involves neural tissue. A 2014 study published in Endocrinology by Jayaraman et al. explored androgen receptor activity in hippocampal neurons and noted that RAD-140 activated neuroprotective pathways in vitro and in an Alzheimer’s disease mouse model. This includes MAPK/ERK signaling cascades. These findings are early-stage and preclinical only.
Androgen Receptor Expression in Breast Cancer Cell Lines
RAD-140 has also appeared in research examining androgen receptor behavior in AR-positive cancer cell lines. A 2017 paper in Clinical Cancer Research by Yu et al. examined RAD-140’s activity in androgen/estrogen receptor–positive breast cancer cell line models, finding selective AR modulation with a mechanism distinct from traditional antiandrogens — findings that generated interest in the oncology research space.
A subsequent Phase 1 clinical study in 22 patients with ER+/HER2- metastatic breast cancer (Yin et al., 2021, Clinical Breast Cancer) noted significant hepatotoxicity signals (elevated AST/ALT in the majority of participants), which is important clinical context for safety discussions. These remain exploratory preclinical observations.
Pharmacokinetic Profile in Animal Models
Oral bioavailability data from rodent pharmacokinetic studies suggest RAD-140 achieves measurable plasma concentrations following oral administration – a key reason why capsule formulations are preferred in many in vivo protocols. Half-life estimates from animal models range from 15 to 20 hours. A 2021 Phase 1 human clinical study (Yin et al.) reported a mean half-life of approximately 44.7 hours in human subjects – substantially longer than preclinical estimates and an important consideration for study design.
How Does RAD-140 Compare to Other SARMs in Preclinical Models?
Researchers working across multiple SARM compounds often reference RAD-140 alongside LGD-4033 (Ligandrol) and MK-2866 (Ostarine) when studying tissue-selective AR modulation. A few distinctions observed in preclinical literature:
- Binding affinity: RAD-140’s Ki of ~7 nM at the AR places it among the higher-affinity SARMs studied preclinically – notably stronger than Ostarine, which demonstrates a weaker binding profile in cell-free assays.
- Anabolic: androgenic selectivity: The 90:1 anabolic-to-androgenic ratio reported for RAD-140 in the Miller et al. rodent model is among the highest reported for any SARM investigated in that study design, though direct head-to-head comparisons across compounds are limited by differences in study methodology.
- Neuroprotective signaling data: RAD-140 has more published preclinical data in neural tissue models than LGD-4033 or Ostarine, making it a more referenced compound in that specific research context.
These comparisons are strictly preclinical and do not imply superiority or safety for any use outside a controlled laboratory setting.
Why Are Capsule Formulations Preferred in RAD-140 Research?
RAD-140 capsules formats have become a standard delivery method in preclinical RAD-140 research for several reasons:
- Dosing precision – RAD-140 capsules allow consistent, pre-measured amounts for standardized study protocols
- Oral bioavailability alignment – RAD-140’s molecular structure is suited to enteral delivery, making capsules a logical format for in vivo models
- Reduced preparation variables – Unlike liquid suspensions, RAD-140 capsules eliminate solvent selection and concentration drift between doses
- Protocol reproducibility – RAD-140 capsules lot consistency, when verified by Certificate of Analysis (COA), enables cleaner cross-study comparisons
For researchers designing oral dosing RAD-140 capsules protocols in rodent or cell-based models, sourcing capsule-form RAD-140 with third-party purity verification is considered best practice in the field.
What Are the Risks and Limitations of RAD-140 Research?
This section is important reading for anyone following research on RAD-140 capsules.
Handling Precautions: RAD-140 should be handled by trained laboratory personnel only, in a controlled environment. Use appropriate PPE including gloves and eye protection. Avoid direct skin contact, inhalation of powder, or mucosal exposure during preparation and handling.
Exposure Risks: RAD-140 is a research compound thought to modulate androgen receptor signaling selectively across tissue types in preclinical models. No human safety profile has been established. Accidental human exposure during laboratory handling is a risk that must be managed through standard biosafety protocols.
Storage: Store RAD-140 capsules and bulk material at controlled room temperature (15–25°C), away from direct light, heat, and humidity. For long-term archival storage of reference standards, −20°C is recommended. Always store in original sealed containers.
Toxicity and Data Limitations: No chronic toxicity data exist for RAD-140 capsules in humans. All findings derive from short-duration preclinical models only.
Hormonal Axis Disruption Risk: As an androgen receptor modulator, RAD-140 carries an uncharacterized risk of suppressing the hypothalamic-pituitary-gonadal (HPG) axis in exposed subjects. Rodent studies suggest dose-dependent suppression of endogenous LH and testosterone. This risk remains undefined for human exposure and must be factored into any research ethics considerations.
Carcinogenicity and Long-Term Safety: No carcinogenicity studies have been conducted on RAD-140 in standard regulatory toxicology formats. The compound’s activity in AR-positive cancer cell lines warrants careful consideration in study design contexts.
Regulatory and IACUC Compliance: RAD-140 capsules are not approved by the FDA or any major regulatory body for human or veterinary use. It is listed as a prohibited substance by the World Anti-Doping Agency (WADA) under S1 Anabolic Agents. Researchers must ensure full institutional compliance before procurement or use. In vivo studies using RAD-140 must comply with applicable IACUC requirements and institutional review procedures.
Where Do Researchers Source RAD-140 Capsules?
For lab-grade RAD-140, researchers typically look for independently third-party tested batches with a Certificate of Analysis (COA) available per lot – verifying compound identity, HPLC purity percentage, heavy metals screening, and absence of common contaminants.
A good search will help you find manufacturers that supply COA-verified and research-grade RAD-140 capsules (Testolone) strictly for preclinical and in vitro research use. It is important to ensure that each batch comes with third-party COA documentation, and the compound is offered verified at the stated purity and certificates for laboratory application.
Conclusion
RAD-140 capsules remains one of the more molecularly characterized SARMs in the preclinical literature, with published data spanning androgen receptor binding, tissue-selective activity, neural signaling, and cancer cell line investigations. Research includes a published Phase 1 human clinical study (2021) documenting significant hepatotoxicity signals. Findings from healthy-subject populations remain absent, and long-term safety data are not established.
For those following this area of androgen receptor modulation research, the RAD-140 capsules format continues to be the preferred delivery vehicle for standardized in vivo protocols – and sourcing from COA-verified suppliers is essential for reproducible results.
For laboratories following this research, BehemothLabz offers COA-verified RAD-140 Testolone capsules for preclinical laboratory use only.
Frequently Asked Questions About RAD-140 Capsules
What is RAD-140 used for in research? RAD-140 (Testolone) is investigated in preclinical settings for its selective androgen receptor modulator (SARM) properties. Laboratory studies have explored its activity in muscle tissue models, neural signaling pathways, and AR-positive cancer cell lines. It is not approved for human or veterinary use, is not a dietary supplement, and is intended strictly for research purposes.
Is RAD-140 approved by the FDA? No. RAD-140 capsules have not received FDA approval for any human or veterinary indication. It remains a research compound with preclinical-only data. Its use is prohibited in competitive sport by WADA under S1 Anabolic Agents and is regulated or restricted in many jurisdictions.
Why do researchers prefer RAD-140 in capsule form? RAD-140 capsules formulations offer consistent pre-measured dosing, eliminate solvent variables present in liquid formats, and align with RAD-140’s orally bioavailable molecular structure. They are preferred in standardized in vivo protocols for these reasons.
What does the preclinical research on RAD-140 show? Preclinical studies have observed selective AR modulation in muscle and reproductive organ tissue models, neuroprotective signaling in hippocampal neuron studies, and AR pathway activity in certain cancer cell lines. A Phase 1 human clinical study (Yin et al., 2021) in 22 patients with ER+/HER2- metastatic breast cancer reported significant hepatotoxicity including elevated AST (59.1%) and ALT (45.5%), with Grade 3/4 adverse events in 72.7% of participants. This represents an important clinical safety context, though the study population was oncology patients on a specific dosing regimen, not healthy subjects.
How does RAD-140 compare to other SARMs like Ostarine or LGD-4033? In preclinical models, RAD-140 exhibits a higher reported anabolic-to-androgenic ratio (~90:1) and stronger AR binding affinity (Ki ~7 nM) than Ostarine. It also has more published neural tissue data than LGD-4033. Direct cross-compound comparisons are limited by differences in study methodology and remain strictly preclinical.
Is RAD-140 legal to purchase for research? In the United States, RAD-140 capsules are not a DEA-scheduled substance, meaning it can be legally procured for legitimate laboratory research purposes. However, it is not approved for human use, is not sold as a supplement, and is prohibited by WADA in sport. Regulatory status varies by country – researchers must verify applicable laws in their jurisdiction before procurement.
Where can researchers source verified RAD-140 capsules? Research institutions typically source RAD-140 capsules from suppliers that provide independent third-party Certificates of Analysis (COA) per batch. A search can provide details about the known suppliers in the research compound community for providing COA-verified material for laboratory use.
What are the main risks associated with handling RAD-140 in a lab setting? Key considerations include accidental dermal or mucosal exposure, potential HPG axis disruption from unintended exposure, absence of chronic toxicity data, undefined carcinogenicity risk, and mandatory IACUC compliance for in vivo protocols. Standard laboratory PPE and biosafety protocols are mandatory when handling this compound.
As with anything you read on the internet, this article on RAD-140 capsules should not be construed as medical advice; please talk to your doctor or primary care provider before changing your wellness routine. WHN neither agrees nor disagrees with any of the materials posted. This article is not intended to provide a medical diagnosis, recommendation, treatment, or endorsement.
Opinion Disclaimer: The views and opinions expressed in this article on RAD-140 capsules are those of the author and do not necessarily reflect the official policy of WHN. Any content provided by guest authors is of their own opinion and is not intended to malign any religion, ethnic group, club, organization, company, individual, or anyone or anything else. The Food and Drug Administration has not evaluated these statements.
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References/Sources/Materials provided by:
- Miller CP, et al. (2011). Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140. ACS Medicinal Chemistry Letters, 2(2), 124–129. https://pubmed.ncbi.nlm.nih.gov/24900290/ DOI: https://doi.org/10.1021/ml1002508
- Jayaraman A, et al. (2014). Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats. Endocrinology, 155(4), 1398–1406. https://pubmed.ncbi.nlm.nih.gov/24428527/
- Yu Z, et al. (2017). Selective Androgen Receptor Modulator RAD140 Inhibits the Growth of Androgen/Estrogen Receptor-Positive Breast Cancer Models with a Distinct Mechanism of Action. Clinical Cancer Research, 23(24), 7608–7620. https://pubmed.ncbi.nlm.nih.gov/28974548/
DOI: https://doi.org/10.1158/1078-0432.CCR-17-0670 - U.S. National Library of Medicine. ClinicalTrials.gov – NCT02987140. https://clinicaltrials.gov/ct2/show/NCT02987140
- World Anti-Doping Agency (WADA). Prohibited List 2026 — S1 Anabolic Agents. https://www.wada-ama.org/en/prohibited-list
