Testosterone Cypionate is a synthetic derivative of testosterone in the form of an oil-soluble 17 (beta)-cyclopentylpropionate ester. It is benet compared to other testosterone derivatives is the slow rate of release after injection and longer half-life. It is usually used in adult men for testosterone replacement to treat various health problems caused by a lack of testosterone. This should be confirmed by two separate blood testosterone measurements and also include clinical symptoms such as impotence, infertility, low sex drive, tiredness, depressive moods and bone loss caused by low hormone levels.