YK11, also known as Myostine, is considered one of the strongest SARMs on the market. In fact, it’s so strong and has a comparable anabolic activity to steroids that it may actually be a synthetic steroid that was mislabeled a SARM in the first place. YK11 was first studied by Japanese researcher Yuichiro Kanno in 2011. It was found to be a partial agonist of the Androgen Receptor (AR) with gene-selective properties, leading researchers to suggest that the compound is a SARM.

To date, limited studies have been undertaken, although preliminary findings in vitro on muscle cells are very promising. Initial studies suggest that YK11 may have greater muscle building effects than those of DHT and a propensity to act as a myostatin inhibitor. As a relatively new compound, exactly how YK11 works to improve lean muscle mass in humans can only be discussed based on initial in vitro studies. However, what we do know is that YK11 may be a Myostatin blocker – essentially allowing users to reap continuous gains without stalling and requiring a break in a cycle.

Myostatin is a protein that is released to limit muscle growth to ensure they do not get ‘too large’. It is found predominantly in skeletal muscle, and studies show that individuals with a gene mutation that limits Myostatin production are both stronger and more muscular than those with normal amounts. YK11 may help to inhibit the production of Myostatin in muscles by attaching itself to the Androgen Receptor. From there, it may induce muscles to create more Follistatin, which in turn limits the levels of Myostatin, allowing increased muscle growth beyond genetic capability.