Although i’d wager most of it ends up in humans, it is still sold as a Vetrinary Steroid. As a vetrinary steroid it was never approved for human use, which makes it impossible to get a prescription for it in the usa. add this to the fact that it is a schedule 2 controlled substance in the united states and it becomes quite clear that the only way to get this steroid in the usa is to buy it on the black market. that being said, it is still relatively easy to obtain the real stuff. This is because smuggling almost 2x as much testosterone in the same space is a rather enticing thing, making it commonly available.
The partition coefficient of the ester in question is important because is effects how long the drug itself stays in the system. If the testosterone transfers too quickly from the oil to the blood, the result is a sudden spike in testosterone which then rapidly drops once the dose has been used up. In the example of free testosterone injected into the muscle from a water suspension (as in Aquiviron, mentioned above), the testosterone is essentially immediately available to the bloodstream due to its low partition coefficient, and thus there is an immediate spike of testosterone which is used up quickly in the body.
While we are familiar with the Propionate ester the remaining three esters that create Sustanon-250 are almost always found as part of a mixture or compounded anabolic androgenic steroid .
Developed by Organon, the original idea behind Sustanon-250 was to provide a testosterone form well-suited for hormone replacement therapy that would only needed to be administered once every few weeks and for all intense purposes the idea was a success. For the performance enhancing athlete Sustanon-250 can be a fine choice but the idea of injecting only once or twice a month is not applicable here. As a performance enhancer this testosterone like all forms will need to be administered on a more frequent basis. This mixture carries with it two fast, short esters, Propionate and Pheylpropionate, a longer more moderate ester Isocaproate and the very slow and long Decanoate ester. In order to keep testosterone levels stable and at their peak most athletes will inject Sustanon-250 at a minimum of every 3 days and more commonly every other day for optimal results.
For more info see: Sustanon-250