Testosterone undecanoate is a form of the male hormone testosterone. It is used to make sustanon and also known as Nebido. After an application the undecanoate ester releases a long lasting effect of testosterone in the bloodstream. This lasts approximately 3 weeks similar to nandrolone decanoate but more than enanthate and cypionate depending on the users metabolism and initial hormone level. To maintain the physiological levels of the testosterone in the body it is necessary to receive applications every 3 weeks to maintain hormone levels.
Testosterone undecanoate is a modified form of the male hormone testosterone. It is an ester of a carboxylic acid-undecanoic acid bound to the 17-beta group. These modified forms of testosterone are not as polarized as the free testosterone which generates slow absorption from the injection site. Once the testosterone undecanoate is in the blood stream, the decanoate ester is separated from the testosterone making it free and active. This type of esterified steroid is designed to prolong the effects of testosterone in the body, requiring less applications compared to other steroids that are not esterified. Testosterone undecanoate has a half life of approximately 3 weeks.
All types of testosterone have the ability to aromatize in the body due to an ester called aromatase, this is also responsible for the conversion of testosterone into estrogen. Due to the prolonged effect of testosterone undecanoate, hormone levels tend to fluctuate after every application increasing the risk for higher estrogen levels in the blood stream. It is essential to use antiestrogens to control estrogen levels and to decrease the risk of gynecomastia, water retention and body fat gain. These types of products have no hepatotoxic effects in comparison to oral substances. Like all androgenic anabolic steroids, testosterone has the ability to reduce the production of endogenous testosterone. Prolonged use could cause hypogonadism which could cause an excessive loss of muscle mass and an imbalance in anabolic and catabolic hormones at the termination of testosterone treatment. It is important to complete a proper post cycle therapy to stimulate the production of endogenous testosterone to avoid losing significant muscle mass in a short period of time.
Testosterone undecanoate is a fine white powder, easy to compress, stable at normal environmental conditions and has a low melting point compared to other substances.
Testosterone undecanoate is an oil base that is generally a very light yellow to transparent in colour.in high concentrations testosterone undecanoate does not crystallize within the vial. The viscosity in comparison to other substances is higher, it is uncommonly found on its own. Generally it is found amongst the four testosterones that make up sustanon.