YK-11 for Muscle Development SARMs
CAS Number: 1370003-76-1
Molar mass: 430.541 g/mol
Appearance: White to Off-White Powder
Synonyms: YK11; ((17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester
The Benefits and Uses:
YK11 is a partial agonist of the androgen receptor with a greater effect on increasing follistatin than DHT does (Kano et all 2013 Selective Androgen Receptor Modulator, YK11, Regulates Myogenic Differentiation of C2C12 Myoblasts by Follistatin Expression). What follistatin does is it inhibits the action of myostatin. Myostatin inhibits the actions of Myf5, MyoD, and myogenin. Myf5, MyoD, and myogenin induces muscle growth. This is excellent news for us but there is a negative aspect of YK11 being a partial agnonist of the androgen receptor. YK11 may inhibit testosterone and DHT from acting on the androgen receptor since it will compete for binding at the androgen receptor with testosterone and DHT. This is something to consider if running YK11 as there is the risk that running DHT compounds and/or testosterone or other androgens may reduce their effectiveness since YK11 will be competing with and taking up some of the androgen receptors. In a low testosterone and/or low DHT state however, YK11 would be beneficial as you have less of a risk for androgen receptor saturation. With that said, even though there is a risk of YK11 being a antiandrogen and that it may be less anabolic than DHT and/or testosterone, the effects on follistatin may counter this potential drawback. This is something which should be considered when deciding to run YK11 with other androgens.