What is KYZATREX™? KYZATREX™ is an FDA-approved oral prescription medication designed for testosterone replacement therapy (TRT). Testosterone replacement therapy is a treatment to replace the testosterone you’ve lost and get your T-levels back to a normal range. TRT has traditionally consisted of testosterone patches, gels, pellets, and injections KYZATREX™ is an oral prescription drug that is used to treat adult men who have low or no testosterone levels due to certain medical conditions.