YK11 10mg

YK11 occupies an ambiguous position in the SARM category. It was originally synthesized as a derivative of 19-nor-testosterone (the same steroid scaffold as nandrolone), and it does bind to the androgen receptor -- but it also appears to act as a myostatin inhibitor through a mechanism separate from AR binding. This dual activity is what makes YK11 pharmacologically interesting and also makes interpreting its research data more complicated than with conventional SARMs.

Myostatin is a naturally occurring negative regulator of myogenesis-pathway activity -- essentially a biological brake on skeletal muscle development. Inhibiting myostatin in animal models produces significant increases in muscle mass, which is why myostatin inhibition has been a target for muscle-pathway research. YK11 appears to reduce follistatin expression in ways that correlate with myostatin pathway modulation, though the precise mechanism remains under investigation. Some researchers characterize it as a partial agonist at AR that simultaneously reduces myostatin's inhibitory effect.

The available research is less extensive than for more established SARMs like Ostarine. Most published work is in vitro (cell culture), with fewer animal studies. This makes it harder to draw confident conclusions about in vivo effects, though the in vitro findings have been interesting enough to sustain ongoing research interest.

Research Applications

YK11 is used in research on muscle satellite cell biology, myostatin pathway pharmacology, and as a model for studying compounds with dual AR agonist and myostatin inhibitory activity. Its structural relationship to 19-nortestosterone also makes it relevant for comparing steroidal versus non-steroidal SARMs at the AR.

Specifications

Storage

Store at -20°C in the original sealed vial. Stable for 24+ months under proper storage. Minimize light exposure during handling. Aliquot dissolved solutions to avoid freeze-thaw degradation.

YK11 is supplied for laboratory research use only. Not approved for human use. Handle in compliance with institutional biosafety guidelines.