YK-11
YK-11 is a steroidal Selective Androgen Receptor Modulator (SARM). Whereas most SARMs are removed from traditional AAS structurally, YK-11 is built on the same common steroid backbone. It is still quite unique, however, and does not closely resemble any common anabolic steroid. This unusual structure may afford it some level of selectivity in action, similar to other SARMs. YK-11 is described as a partial AR agonist. It appears to activate the androgen receptor, though in some tissues may not result in full transcribing activity. As such, it could have a reduced level of relative androgenicity. Admittedly though, the classification of YK-11 as a SARM is a tenuous one. This drug is in an early stage of research.Thus far, it has only been subject to in-vitro (cell incubation) studies. These investigations did report several interesting findings, however. First, YK-11 did bind and activate the androgen receptor similar to traditional AAS (dihydrotestosterone).
It was found to be a partial agonist of this receptor though, and displayed gene-selective activity. Its profile could resemble that of a classic non-steroidal SARM. As such, it might augment anabolic processes, but with muted androgenic activity. YK-11 was also shown to strongly stimulate the release of follistatin. This is an important protein for muscle growth, as it strongly antagonizes myostatin, a growth inhibitor. Some AAS also share this activity, though it was particularly noteworthy in this case. YK-11 appears to have certain favorable properties on paper. This could be an effective steroidal muscle builder, with reduced SARM-like androgenicity in certain tissues. However, not having been subject to even animal testing at this point, it is far too early to speculate on its efficacy and safety in humans. In spite of this, YK-11 is popular in the fitness community, where it is used as a muscle-building alternative to anabolic steroids. Of course, there are other drugs in the SARM category with similar anabolic effects and a significantly larger body of research behind them. We recommend a full review of this category.