General Information. Testosterone was the first ever synthesized anabolic steroid, and testosterone cypionate is a slow-acting, long-ester, oil-based injectable testosterone compound that is commonly prescribed for the treatment of hypogonadism – low testosterone levels and various related symptoms in males.he Cypionate Ester: An ester is any of a class of organic compounds that react with water to produce alcohols and organic or inorganic acids. Most esters are derived from carboxylic acids, and injectable testosterone is typically administered along with one or multiple esters.