The goal of testosterone replacement therapy (TRT) is to return serum testosterone levels to within physiologic range and improve symptoms in hypogonadal men. Some of the symptoms aimed to improve upon include decreased libido, erectile dysfunction, infertility, hot flashes, depressed mood, and loss of muscle mass or hair. Clinical use of testosterone for replacement therapy began approximately 70 years ago. Over the decades, numerous preparations and formulations have been developed primarily focusing on different routes of delivery and thus pharmacokinetics (PKs). Currently the routes of delivery approved for use by the United States Food and Drug Administration encompasses buccal, nasal, subdermal, transdermal, and intramuscular (IM). Many factors must be considered when a clinician is choosing the most correct formulation for a patient. As this decision depends highly on the patient, active patient participation is important for effective selection. The aim of this review is to describe and compare all testosterone preparations currently available and approved by the United States Food and Drug Administration. Areas of focus will include pharmacology, PKs, adverse effects, and specifics related to individual delivery routes.



When considering all available routes of delivery, concentrations, and branded or generic choices, there are currently over 30 different testosterone preparations to consider when choosing one for a patient. The decision on the best product choice should include patient preference, PKs, treatment burden, cost and insurance coverage. Products may also need to be switched throughout TRT based upon patient response, preference, and adverse effects. In all circumstances, the decisions should be an open dialogue between the patient and clinician to allow for the most successful TRT regimen.


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Cognitive Ability Testosterone