Description Cypionate® is a steroid compound that is described chemically as 17β-Hydroxyandrost-4-en-3-one cyclopentanepropionate. It is the principal hormone of the testis. The ester, Cypionate, is a white or creamy-white crystalline powder, odourless or has a slight odour that is insoluble in water, freely soluble in alcohol, soluble in vegetable oil. Esterification of the 17 beta-hydroxy group produces compounds which have a longer duration of action