YK11

YK-11 is a steroidal compound that acts on androgen receptors and is generally grouped with SARMs. It is primarily of interest for muscle-building and body-composition goals, with laboratory research also showing an unusual effect on follistatin, a protein involved in regulating muscle development.

YK-11 activates androgen receptors involved in muscle development. Laboratory research also found that it increased follistatin, which can counter myostatin-related signalling — essentially one of the body’s natural systems for limiting how much muscle develops. These findings come from laboratory research rather than human muscle-building trials.

Its appeal comes from potentially influencing muscle development in two interesting ways: androgen-receptor activity combined with increased follistatin in laboratory research. This gives YK-11 a distinctive muscle-building theory, although actual increases in muscle mass or strength from YK-11 have not been established in controlled human trials.

Not directly based on the available research. Laboratory studies found that YK-11 increased follistatin, a protein capable of opposing myostatin activity. Myostatin normally acts as a brake on muscle development, so this finding helps explain the interest in YK-11, but calling it a proven human myostatin blocker would overstate the evidence.

Both are associated with muscle-building goals, but their evidence is very different. LGD-4033 has controlled human trials showing increases in lean body mass, while YK-11’s appeal centres on laboratory findings involving androgen signalling and follistatin. LGD-4033 therefore has much stronger direct human evidence for lean-mass gains.

There is not enough controlled human research to establish a reliable side-effect profile for YK-11. Because it has androgen-receptor activity, hormone-related effects are a reasonable concern, but there is not enough clinical evidence to confidently state how frequently particular effects occur in people.

Orders are packed discreetly and shipped within Australia via Australia Post Express, with tracking provided once your order has been dispatched.

Orders are dispatched within one business day and sent via Australia Post Express, with delivery usually taking 2–3 business days.