YK11 is a new synthetic steroid based on 5-α-dihydrotestosterone (DHT), a hormone naturally found in the human body. DHT is a stronger form of testosterone that targets androgen receptors in the prostate, sex organs, hair, and liver.
Some bodybuilders who have experimented with YK11 report great muscle gains and fat loss with minimal side effects. However, there are currently not even any animal studies of YK11 and its safety profile is unclear.
Is It a SARM?
Bodybuilders and researchers sometimes refer to YK11 as a SARM (selective androgen receptor modulator). This may be misleading as other SARMs differ from YK11.
YK11 is a steroid made by altering the chemical structure of DHT. In contrast, all other SARMs have a nonsteroidal structure. YK11 and SARMs work differently in the body and may have different side effects [2, 6].
Cell studies do show that YK11 has a selective effect on androgen receptors. This means the SARM label does technically describe YK11 .
Because this class of drugs is new, no established naming convention exists.
How Does It Work?
The chemical structure of YK11 is similar to DHT, and it binds to androgen receptors in a similar way. DHT is a naturally occurring hormone in the body crucial for hair growth, prostate health, and proper development in puberty.
Some bodybuilding resources state that YK11 is one of the strongest SARMs on the market. However, research revealed that YK11 only partially activates androgen receptors.
A recent cell study uncovered YK’s unique muscle-building mechanism: increasing follistatin levels. Follistatin is a naturally occurring protein that suppresses myostatin, which otherwise prevents muscles from getting too large. In comparison, no other SARMs show myostatin inhibition .
YK11 may also increase bone growth by affecting a DHT-like pathway, according to other cellular studies. However, it is unclear whether this mechanism would transfer to living animal or human systems .