This is a pretty rare version of testosterone, as it has the phenylpropionate ester attached. This ester is much more commonly attached to the nandrolone base compound, giving us Durabolin (often called NPP, which is short for Nandrolone Phenylpropionate). Here, the ester is attached to the testosterone base compound, giving a short/medium estered product, which results in an active life of 4-5 days. Clearly, you'd get best results shooting this compound every fourth day, or twice a week.