Ostarine
MK-2866 — The Foundational SARM
01
Overview
Ostarine (MK-2866, Enobosarm) is one of the first SARMs to enter human clinical trials, developed by GTx Inc. for cancer cachexia and muscle wasting. It has an extensive clinical dataset spanning multiple Phase II and Phase III trials, providing the most robust human safety and efficacy data of any SARM currently in development.
02
Mechanism of Action
Ostarine selectively binds the androgen receptor with moderate affinity, demonstrating tissue-selective partial agonism. In muscle it acts as a full agonist with anabolic effects, while in reproductive tissue it shows partial activity, resulting in a favorable anabolic-to-androgenic selectivity ratio.
03
Research Highlights
Phase III POWER trial in cancer cachexia shows significant lean mass preservation
Phase II trials demonstrate improvement in functional performance measures
Biomarker studies confirm bone formation improvement without prostate-specific antigen elevation
04
Dosage
Administration & Timing
Oral administration (capsule or solution), once daily. Research protocols administer independent of food.
Dosage Guidelines
Cycle Length
8–12 weeks; followed by 4 week rest and PCT evaluation.
05
Reconstitution
Solvent
Not applicable — orally dosed capsule or solution
Volume
N/A
Concentration
12.5–25 mg per unit dose
Storage
Store at room temperature (15–25 °C); protect from moisture.
Notes
Ostarine (MK-2866, Enobosarm) is the most clinically studied SARM. Investigational — suppresses testosterone at higher doses.
Research Reference Only
Dosage and reconstitution values reflect commonly cited ranges from published research literature and are presented for educational and research reference only. This is not medical advice or a dosing recommendation. HEXAGEN does not endorse human use of any compound. Always consult a qualified healthcare professional.
Research Disclaimer
Ostarine is for educational and research purposes only. Not intended as medical advice. Consult a qualified healthcare professional before making any health-related decisions.
Related Compounds
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Ostarine — Common Research Questions
What is Ostarine?
Ostarine (MK-2866, Enobosarm) is one of the first SARMs to enter human clinical trials, developed by GTx Inc. for cancer cachexia and muscle wasting. It has an extensive clinical dataset spanning mult... Ostarine belongs to the Non-Peptide Research research category and is studied for its mk-2866 — the foundational sarm.
How does Ostarine work?
Ostarine selectively binds the androgen receptor with moderate affinity, demonstrating tissue-selective partial agonism. In muscle it acts as a full agonist with anabolic effects, while in reproductive tissue it shows partial activity, resulting in a favorable anabolic-to-androgenic selectivity ratio.
What are the key research benefits of Ostarine?
Lean muscle mass preservation and mild increase. Cancer cachexia and muscle wasting research. Improved physical function and stair climb power. Joint and connective tissue benefit in research. Mild anabolic effects with minimal androgenic activity. One of the most clinically researched SARMs.
What is the molecular structure of Ostarine?
Ostarine is a research compound in the Non-Peptide Research category. Detailed molecular structure data is being compiled. Refer to primary literature for structural analysis.
What does the research say about Ostarine?
Phase III POWER trial in cancer cachexia shows significant lean mass preservation Phase II trials demonstrate improvement in functional performance measures Biomarker studies confirm bone formation improvement without prostate-specific antigen elevation These findings are based on preclinical and clinical research. Ostarine is a research compound and these studies do not constitute medical advice.
Is Ostarine FDA approved?
No. Ostarine is not FDA-approved for any indication. It is a research chemical studied in preclinical and early clinical research. These compounds are not approved for human therapeutic use and should only be studied in appropriate research settings.
What category does Ostarine belong to?
Ostarine belongs to the Non-Peptide Research category, which focuses on selective androgen receptor modulators and other novel research compounds studied for their unique pharmacological profiles. You can explore more compounds in this category on the Non-Peptide Research pillar page.
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Scientific References
Dalton et al. — "Enobosarm: foundational SARM" (J Cachexia Sarcopenia Muscle, 2011)
POWER Phase III trial in cancer cachexia
Phase III POWER trial in cancer cachexia shows significant lean mass preservation
Phase II trials demonstrate improvement in functional performance measures
Biomarker studies confirm bone formation improvement without prostate-specific antigen elevation