Testosterone undecanoate (USAN, BAN) (brand names Aveed, Andriol, Androxon, Cernos Depot, Nebido, Panteston, Restandol, Nebido-R, Reandron 1000, Undestor), or testosterone undecylate, is an androgen and anabolic steroid and a testosterone ester. It is used in androgen replacement therapy primarily for the treatment of male hypogonadism, and has also been investigated for use as a male contraceptive. Unlike other testosterone esters, testosterone undecanoate is available in both oral and intramuscular formulations.