Information about Testosterone undecanoate

Testosterone undecanoate or testosterone undecylate is an ester of testosterone. This hormone is used in androgen replacement therapy primarily for the treatment of male hypogonadism, and is currently under research for use as a male contraceptive.
Andriol is a unique oral testosterone product, developed by the international drug firm Organon. One of the more recently developed anabolic steroids, Andriol first became available in the early 1980's. This compound contains 40 mg of testosterone undecanoate, based in oil (oleic acid) and sealed inside a capsule. Subtracting the ester weight, this equates to a dosage of approximately 25mg of raw testosterone per cap. The design of this steroid is quite different from that of most oral steroids. Drugs administered orally generally enter the blood stream through the liver. When a steroid compound is given this way without some form of structural protection, it will be quickly broken down during the "first pass". This process leaves very little steroid intact, basically deactivating the drug. Adding a methyl group (c-17 AA) to the structure is one way to protect it from this process, however stress is also placed on the liver as a result. In some instances this stress can lead to actual damage to liver tissues, so the designers of this steroid sought another way to protect the testosterone molecule. With Andriol, this was accomplished by making a form of testosterone that would be absorbed through the lymphatic system. This is due to its high fat solubility brought about by the ester, and its suspension in oil. Having the compound absorbed this way was thought to be very advantageous, as it allows the steroid to bypass the destructive first-pass through liver. This should permit the compound to enter the blood stream intact, without the need for a harsh chemical alteration. The ester breaks off once it is in circulation of course, yielding free active Pharmacokinetics of Orai Testosterone testosterone. In design this steroid appears to be undecanoate that of a completely liver safe and orally active form of testosterone.