Outcomes of Direct Vocal Fold Testosterone Injections in Hormone-Naïve Adults: A Case Series

Two nonbinary testosterone-naïve individuals were seen at the Northwestern Memorial Hospital Voice Clinic. The objective was to determine the effectiveness of direct testosterone injections to the vocal folds for voice masculinization in testosterone-naïve individuals. Both subjects underwent 4 direct testosterone injections to the bilateral vocal folds 2 weeks apart. Before each injection, and 1 and 3 months post final procedure, the following were completed: voice recordings, voice-related quality of life survey, and mini-mood and anxiety questionnaire. Serum hormone levels were assessed pretreatment and posttreatment. Linear regression indicated a significant decrease in mean F0 3 months postfinal injection in both participants. Both reported improved voice quality of life and voice qualities shifted towards prototypical male. No systemic side effects reported, and posttreatment testosterone and estradiol levels were similar to baseline. Direct testosterone injections into the vocal folds represent a promising therapeutic intervention for voice masculinization in testosterone-naïve individuals.