What is YK11?
YK11 is the latest flavor of the month in the underground gray market bodybuilding supplement world. YK11 is a stero molecule that has only been shown to have effects in cellular assays. This means that there are no published results in animals or humans as yet. Even so it has popped up for sale on the internet as an anabolic SARM or SARM.
New age SARMs like LGD-4033 and Ostarine are non-stero, meaning that they do not have the typical four ring structure of classical androgens like Stero like Nan and perhaps tre can be considered to be SARMs since they convert through 5-alpha reduction to less potent androgens and in reasonable doses show more anabolic than androgenic effects. Stero has been turned into a bad word so for the most part, companies are developing non-stero SARMS. In reality,it makes little difference the shape of the molecule but rather what its effects are.
YK11 is stero. In fact, it looks a lot like. The two papers that are available show that YK11 can activate the androgen receptor but that it does so only partially. This results in an effect known as partial agonism. This means that YK11 can potentially displace stronger androgens while exerting a lower overall stimulating effect on the receptor. In fact the paper by Kanno et al demonstrates this effect by bathing cells in DHT alone or in DHT + YK11. Those cells that received both DHT and YK11 had less androgenic stimulation than with DHT alone. This is important since, in the presence of stronger androgens, YK11 will actually reduce androgen receptor stimulation. In the case of the prostate or hair follicle, this can be a good thing. In skeletal muscle, this will not be a good thing.