Different testosterone esters are often blended into one injectable preparation. In some cases up to seven esters are used, but the most popular formulation is that of Sustanon 250 where four esters are mixed together. This is done to take advantage of the faster acting esters while still only requiring weekly or bi-weekly injections. It is often believed to be a superior form of testosterone, but in reality it’s nothing more than just testosterone. One drawback of testosterone blends are that they incorporate esters with long carbon chains and those chains occupy allot of molecular weight, so the actual dosage of hormone is less than one would obtain from shorter esters like propionate. Testosterone blends are most useful during bulking phases where frequent injections are not possible.