The best method for administering testosterone replacement therapy (TRT) for late-onset hypogonadism (LOH) remains controversial. This study aimed to compare the efficacy and safety of a combined treatment (CT) involving intramuscular testosterone injection and testosterone ointment application [Glowmin (GL)] with intramuscular injection monotherapy (IMIM). Patients were randomly assigned as follows: Group 1 received IMIM for 12 weeks and CT for 12 weeks and Group 2 received CT for 12 weeks and IMIM for 12 weeks. Patients were then asked about their treatment preferences: (A) IMIM, (B) a combination of IMIM and ointment, or (C) either A or B. Patients ( = 43) completed the study without any adverse effects. No significant differences between each treatment period were found. In Group 1, most patients chose B ( = 13) while in Group 2, most chose A ( = 10). In each group, patients preferred the second treatment phase; however, statistical significance was not reached between A and B (Group 1,  = 0.11 and Group 2,  = 0.47, respectively). TRT by CT is compatible with TRT by IMIM. Patients who cannot continue TRT because of polycythemia from IMIM may be suited to CT.