The FDA has approved two new oral formulations of testosterone undecanoate — Kyzatrex (Marius) and Tlando (Antares) — for treatment of males with a deficiency of endogenous testosterone due to conditions such as Klinefelter syndrome, orchiectomy, toxic damage from chemotherapy or alcohol, or pituitary-hypothalamic injury caused by tumors, trauma, or radiation. Jatenzo, another oral testosterone undecanoate formulation, was approved for the same indication in 2019. No testosterone products are approved for treatment of low testosterone levels due solely to aging.

Three coordinated double-blind, placebo-controlled clinical trials have evaluated the efficacy of one year of testosterone replacement therapy in improving sexual function, physical function, and vitality in a total of 790 men ≥65 years old with moderately low serum testosterone concentrations and symptoms suggesting hypoandrogenism. Sexual function improved modestly, and there appeared to be marginal benefits in some areas of physical function and vitality as well. The trials were not designed to evaluate the safety of testosterone replacement therapy.

The FDA has approved an intranasal gel formulation of testosterone (Natesto – Trimel/Endo) for replacement therapy in men with hypogonadism. Packaged in a metered-dose pump, Natesto is the first intranasal testosterone to become available in the US. Like other testosterone products, it is classified as a schedule III controlled substance. The FDA recently cautioned against using testosterone to treat low testosterone levels solely due to aging because the benefits and safety of such use have not been established, and there is a possible increased risk of myocardial infarction (MI) and stroke.

The FDA has approved testosterone undecanoate (Aveed – Endo), an injectable depot formulation, for use in men with hypogonadism who require testosterone replacement therapy.

The Medical Letter recently reviewed a topical gel formulation of testosterone (Fortesta) for treatment of hypogonadism in men. A topical testosterone replacement product for application to the axilla, Axiron (Lilly) solution, has now become available for the same indication. This site of application presumably minimizes the risk of transferring the drug to a family member or sexual partner.

The FDA has approved Fortesta (Endo), a topical gel, for testosterone replacement therapy in adult males with hypogonadism. It is classified as a Schedule III controlled substance. Table 1 lists some available testosterone products, including 2 other gels.