Sustanon 250 is a trade name for an oil-based injectable blend of four esterized testosterone compounds: 30 mg testosterone propionate, 60 mg testosterone phenylpropionate, 60 mg testosterone isocaproate, 100 mg testosterone decanoate. The different testosterone esters provide for different half lives. Esterization of the testosterone molecules provides for a sustained release of testosterone from the injection depot into the blood plasma. Sustanon is a very popular anabolic steroid product among those that use anabolic steroids for muscle building purposes. 250mg per ml, 10ml vial =2500mg