Testosterone undecanoate (17beta;-undecyloxy-4- androsten-3-one) is an unsaturated,
aliphatic, fatty acid ester of T. Testosterone undecanoate for intramuscular administration
provides a long-acting testosterone depot (half-life of 33.9 +/- 4.9 days) with favorable
pharmacokinetic properties. In hypogonadal men, 1000 mg of Testosterone undecanoate
can maintain stable plasma T levels for 12 weeks.