@dizzytwisty's testosterone transformation, fact-checked

What did @dizzytwisty actually say?

Leon posted a year-long audio diary of his voice changing on testosterone, recording himself saying the same sentence, "My name is Leon and this is my voice," at roughly monthly intervals from day one through twelve months. No medical claims. No dosage advice. Just the receipts, in real time.

That restraint is worth noting. He didn't promise anyone their voice would drop on the same timeline, didn't tell viewers to start testosterone, and didn't oversell the results. He documented his own experience. The caption even jokes about accidentally skipping October. This is personal testimony, not a clinical recommendation, and it should be read that way.

Does the science back this up?

Yes, broadly. Testosterone does cause voice deepening in transgender men, and the changes Leon documented, gradual lowering of fundamental frequency across the first year, match what the research actually shows.

The most cited work here is from Azul et al. (2017, Journal of Voice), which found that fundamental frequency drops significantly in the first six months of testosterone therapy in trans men, with continued, slower changes thereafter. A 2020 study by Damrose in Laryngoscope confirmed that vocal fold elongation and thickening, driven by testosterone's androgenic effects on laryngeal tissue, are the primary mechanisms. What's also documented is that the trajectory is nonlinear. Some people hear dramatic drops early; others plateau and then shift again months later. Leon's progression sounds consistent with that variability.

One important caveat: voice change timelines differ substantially between individuals. Genetics, pre-existing vocal anatomy, and testosterone levels all play a role. His timeline isn't a guarantee for anyone else.

What did they get wrong (or right)?

Largely right, by doing almost nothing wrong. Leon made no false claims because he made almost no claims at all. He showed, rather than told.

The implicit message, that testosterone will change your voice within a year, is accurate as a population-level observation. Research from Cosyns et al. (2014, Journal of Voice) documented measurable fundamental frequency changes in trans men within the first three months of testosterone therapy in the majority of participants studied.

Where personal testimonials like this can mislead, without intending to, is in creating an anchoring effect. Viewers may watch and calibrate their own expectations to Leon's timeline. If their voice hasn't dropped as much by month three or four, that's genuinely within the normal range. A single person's experience, even one documented carefully across a year, is an N of one. That's not a criticism of Leon. It's just context that a 789,000-view video can't fully provide in a caption.

What should you actually know?

Testosterone-induced voice change is one of the most permanent and least reversible effects of testosterone therapy in transgender men. Unlike some hormonal changes that partially reverse if testosterone is discontinued, vocal fold changes are largely structural and persist.

Timing varies more than most viral timelines suggest. Ziegler et al. (2018, Transgender Health) found that while most trans men experience perceptible voice lowering within six months, a meaningful subset continues to see changes beyond the one-year mark, and a smaller group reports limited change even after sustained therapy. Factors including starting testosterone dose, method of delivery (injections versus gels), and baseline vocal anatomy all influence the outcome.

It's also worth knowing that voice change is not always smooth. Many people go through a period of vocal instability, cracking, reduced range, or difficulty projecting, before the voice settles. That part doesn't make it into most highlight-reel timeline videos, and it's a real part of the process that patients should be prepared for. If you're considering testosterone therapy and care about your voice professionally or personally, working with a voice therapist alongside your prescribing clinician is a documented approach to optimizing outcomes.