RESEARCH USE ONLY
20mg per ml
MK-2866
Ostarine · CAS: 841205-47-8
Certificate of Analysis
Batch HPLC & MS included
UK Dispatch
Shipped next working day
Research Grade
≥98% documented purity
Discreet Packaging
Plain, secure, tamper-evident
Laboratory Research Use Only: This compound is sold exclusively for qualified in-vitro scientific and laboratory investigation. Strictly not intended for human or veterinary administration.
Product Overview
MK-2866 (Ostarine), also known as Enobosarm or GTx-024, is a synthetic, non-steroidal selective androgen receptor modulator (SARM) developed for investigation of androgen receptor signalling, skeletal muscle biology, and conditions associated with muscle wasting.
Unlike anabolic steroids, MK-2866 was designed as a tissue-selective androgen receptor modulator, making it an important research compound for studying how selective activation of the androgen receptor can influence muscle and bone tissue.
Enobosarm has progressed considerably further through clinical research than many compounds marketed within the SARM category. Studies have investigated its effects on lean body mass, physical function, cancer-associated muscle wasting, and androgen receptor-positive cancers. Research-Chem.uk MK-2866 is supplied strictly for laboratory research and analytical purposes. It is not intended for human or veterinary use.
| Key Product Features | |
|---|---|
| Compound | MK-2866 |
| Common Name | Ostarine |
| Scientific Name | Enobosarm |
| Alternative Names | GTx-024 / S-22 |
| Compound Class | Non-steroidal SARM |
| Primary Target | Androgen receptor |
| CAS Number | 841205-47-8 |
| Molecular Formula | C₁₉H₁₄F₃N₃O₃ |
| Molecular Weight | 389.3 g/mol |
| PubChem CID | 11326715 |
| Testing | HPLC verified |
| Documentation | Batch-specific Certificate of Analysis (COA) |
| Application | Laboratory research only |
| Dispatch | UK |
What Is MK-2866 (Ostarine)?
MK-2866 is the development code for Enobosarm (GTx-024), a non-steroidal SARM that selectively interacts with the androgen receptor (AR). Its chemical identity is distinct from testosterone and traditional anabolic-androgenic steroids. The compound was developed to investigate anabolic signalling while attempting to produce greater tissue selectivity than conventional androgenic agents.
MK-2866 is also known by several names, including:
- Ostarine
- Enobosarm
- GTx-024
- MK-2866
- S-22
According to PubChem, Enobosarm has the molecular formula C₁₉H₁₄F₃N₃O₃ and a molecular weight of approximately 389.3 g/mol. Its CAS Registry Number is 841205-47-8.
How Is MK-2866 Investigated in Research?
The primary research interest in MK-2866 centres on its interaction with the androgen receptor. Androgen receptor signalling plays an important role in regulating gene expression in tissues including skeletal muscle and bone. MK-2866 provides researchers with a pharmacological tool for investigating selective androgen receptor activation without using a conventional steroidal androgen.
Research involving Enobosarm has examined:
- Androgen receptor activation
- Skeletal muscle signalling
- Lean body mass
- Muscle wasting and cachexia
- Physical function
- Bone and musculoskeletal biology
- Androgen receptor-positive cancers
- Pharmacokinetic and pharmacodynamic characteristics
- Tissue-selective androgenic activity
Preclinical studies have also investigated the molecular pathways through which Enobosarm influences skeletal muscle and androgen-responsive gene expression.
MK-2866 Research Applications
Androgen Receptor Research
MK-2866 is useful as a research compound for studying selective androgen receptor signalling. Researchers can investigate receptor activation, downstream gene expression, and differences between selective androgen receptor modulators and conventional androgenic compounds.
Skeletal Muscle Research
One of the principal areas of Enobosarm research has been skeletal muscle biology. A Phase II study involving healthy elderly men and postmenopausal women reported dose-dependent increases in total lean body mass, alongside changes in physical-function measures.
These findings have contributed to continued interest in selective androgen receptor modulation as a research approach to muscle-wasting conditions.
Muscle-Wasting and Cachexia Research
Enobosarm has been extensively investigated in the context of cancer-associated muscle wasting. A randomised Phase II trial investigated Enobosarm in patients with cancer and reported increases in total lean body mass in the Enobosarm groups compared with baseline.
This makes MK-2866 particularly relevant to laboratory research examining anabolic signalling, muscle preservation, and the biological mechanisms underlying cachexia.
Oncology and Androgen Receptor Research
More recently, Enobosarm has also been investigated in androgen receptor-positive, oestrogen receptor-positive, HER2-negative advanced breast cancer. A Phase II clinical trial published in The Lancet Oncology investigated Enobosarm at two dose levels and reported clinical benefit in a subset of participants, while also documenting treatment-related adverse events including elevated hepatic transaminases. This research demonstrates the broader scientific relevance of androgen receptor modulation beyond skeletal muscle.
What Does the Research Say?
MK-2866 is one of the more extensively studied compounds within the SARM class.
Human Research
Clinical studies have provided evidence that Enobosarm can influence lean body mass and physical function. In a 12-week Phase II study of 120 healthy elderly men and postmenopausal women, Enobosarm produced dose-dependent increases in total lean body mass, with additional effects observed in selected physical-function measures. A separate Phase II cancer-cachexia study reported increases in lean body mass following Enobosarm treatment compared with baseline.
These findings are scientifically important because they provide controlled human evidence of biological activity rather than relying solely on laboratory or animal models.
Clinical Research Does Not Equal General Human Use
The existence of clinical trials should not be interpreted as evidence that MK-2866 is an approved general-purpose supplement or suitable for unsupervised use. Clinical research takes place under defined protocols, with specific participant populations, monitoring procedures, inclusion criteria, and safety assessments. Research outcomes therefore need to be interpreted within the context of the individual study.
Safety Research
Safety is an important part of MK-2866 research. Published case reports have associated Enobosarm with significant drug-induced liver injury, including cholestatic and hepatocellular patterns. Clinical oncology research has also reported treatment-related increases in hepatic transaminases among some participants. These findings reinforce the importance of distinguishing research evidence of biological activity from assumptions about safety.
Research References
-
Dalton et al. — Enobosarm and Lean Body Mass
Dalton JT, et al. (2011). 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 trial.
PMID: 22031847 · DOI: 10.1007/s13539-011-0034-6
This Phase II study investigated Enobosarm in healthy elderly men and postmenopausal women and reported dose-dependent increases in lean body mass.
-
Dobs et al. — Cancer-Associated Muscle Wasting
Dobs AS, et al. (2013). Effects of enobosarm on muscle wasting and physical function in patients with cancer: a double-blind, randomised controlled phase 2 trial.
PMID: 23499390 · DOI: 10.1016/S1470-2045(13)70055-X
This Phase II trial investigated Enobosarm in patients with cancer-associated weight loss and evaluated changes in lean body mass and physical function.
-
Palmieri et al. — Enobosarm in Breast Cancer
Palmieri C, et al. (2024). Activity and safety of enobosarm, a novel, oral, selective androgen receptor modulator, in androgen receptor-positive, oestrogen receptor-positive, and HER2-negative advanced breast cancer. The Lancet Oncology.
PMID: 38342115 · DOI: 10.1016/S1470-2045(24)00004-4
This Phase II study investigated Enobosarm in advanced AR-positive breast cancer and provides more recent clinical data concerning both activity and safety.
-
Bedi et al. — Drug-Induced Liver Injury
Bedi H, et al. (2021). Drug-Induced Liver Injury From Enobosarm (Ostarine), a Selective Androgen Receptor Modulator.
PMID: 34368386 · DOI: 10.14309/crj.0000000000000518
This case report describes significant cholestatic liver injury associated with Ostarine/Enobosarm.
-
PubChem — Enobosarm Chemical Information
PubChem CID: 11326715. Enobosarm / Ostarine / MK-2866. Molecular formula: C₁₉H₁₄F₃N₃O₃. Molecular weight: 389.3 g/mol. CAS: 841205-47-8.
MK-2866 Product Specifications
| Property | Specification |
|---|---|
| Compound | MK-2866 |
| Common Name | Ostarine |
| Scientific Name | Enobosarm |
| Development Code | GTx-024 / MK-2866 |
| Compound Class | Non-steroidal SARM |
| Primary Target | Androgen receptor |
| CAS Number | 841205-47-8 |
| PubChem CID | 11326715 |
| Molecular Formula | C₁₉H₁₄F₃N₃O₃ |
| Molecular Weight | 389.3 g/mol |
| Research Classification | Investigational research compound |
| Testing Method | HPLC |
| Documentation | Batch-specific COA |
| Intended Application | Laboratory research only |
Chemical identification data are based on the PubChem compound record for Enobosarm. Product-specific vial size, quantity and batch purity should be stated according to the corresponding Research-Chem.uk batch documentation rather than assumed from the compound identity.
Quality and Purity
At Research-Chem.uk, analytical verification is an important part of our research-compound supply process. Each batch is submitted for HPLC analysis by an independent UKAS-accredited laboratory, with batches required to meet the applicable purity threshold before approval for dispatch.
A batch-specific Certificate of Analysis (COA) is available to document analytical testing and reported purity.
For researchers, independent analytical verification is particularly important with compounds such as SARMs, where studies have demonstrated considerable variability in products marketed through unregulated channels. Research-Chem.uk therefore focuses on traceability, analytical verification and transparent batch documentation rather than unsupported purity claims.
Laboratory Research Applications
MK-2866 may be of interest to qualified research laboratories investigating:
- Androgen receptor pharmacology
- Selective androgen receptor modulation
- Skeletal muscle signalling
- Muscle protein and anabolic pathways
- Muscle wasting and cachexia
- Sarcopenia-related research
- Bone and musculoskeletal biology
- Androgen-responsive gene expression
- Oncology and androgen receptor biology
- Comparative SARM research
- Analytical chemistry and compound identification
- Pharmacokinetic and pharmacodynamic research
The compound should be handled in accordance with appropriate laboratory chemical-safety procedures and institutional requirements.
Why Choose Research-Chem.uk?
Laboratory-Focused Supply
Research-Chem.uk specialises in research compounds intended for laboratory and analytical applications.
Independent HPLC Testing
Our research compounds are subjected to independent HPLC analysis through a UKAS-accredited laboratory.
Batch Documentation
A Certificate of Analysis provides batch-specific analytical information and supports research traceability.
Research-Only Positioning
We do not market MK-2866 as a dietary supplement, bodybuilding product, medicine, or treatment.
Scientifically Accurate Information
Our product information distinguishes between established chemical identity, preclinical research, human clinical evidence, and claims that remain unproven.
Research-Use Disclaimer
For laboratory research use only. Not for human or veterinary use.
MK-2866 (Ostarine/Enobosarm) is supplied by Research-Chem.uk strictly for laboratory research and analytical purposes.
This product is not intended for human consumption, veterinary use, diagnosis, treatment, prevention of disease, or use as a dietary supplement.
MK-2866 is an investigational selective androgen receptor modulator. Although Enobosarm has been evaluated in clinical research, investigational research findings should not be interpreted as evidence that the compound is appropriate or approved for general human use.
Published research has also identified potential safety concerns, including reports of drug-induced liver injury and treatment-associated hepatic enzyme elevations.
Researchers are responsible for ensuring that all handling, storage, analysis and disposal of the compound comply with applicable institutional, laboratory and regulatory requirements.
For laboratory research only. Not for human or veterinary use.
