TikTok's testosterone diary gets the basics right

What did @transfaerieprince actually say?

Two weeks into low-dose testosterone gel therapy, the creator reports a small voice drop in week one that has since plateaued, improved energy, and what they describe as greater emotional stability. They're using 2.5 grams of gel daily, which they characterize as roughly half to a quarter of a standard dose. They also mention plans to try Jamaican black castor oil and peppermint oil for beard growth, and they explicitly avoided minoxidil because of concern about toxicity to their cats.

This is a personal experience video, not medical advice, and the creator is upfront about that framing. They're documenting a journey in real time. The claims are mostly modest and hedged appropriately for a two-week window. That said, a few things in here deserve a closer look, because not everything they believe about their regimen holds up under scrutiny.

Does the science back this up?

Mostly, yes, with some important caveats. Voice changes in the first weeks of testosterone therapy are real and documented, but the timeline varies significantly. The castor oil claim for beard growth is not supported by credible evidence. The minoxidil-cat toxicity concern, however, is legitimate.

On voice: testosterone-induced vocal changes are mediated by laryngeal cartilage growth and muscle hypertrophy. A 2016 study by Azul et al. in the International Journal of Transgender Health confirmed that voice pitch changes are among the earliest reported changes in transmasculine individuals on testosterone, often beginning within the first few weeks. That said, early changes frequently plateau and then resume, so the creator's experience of a plateau at week two is consistent with how this actually works.

On emotional regulation: there's legitimate science here. A 2018 study by Colizzi et al. in Psychoneuroendocrinology found that gender-affirming hormone therapy was associated with reduced psychological distress and improved emotional regulation over time. The creator's specific framing, that testosterone reduces the emotional rollercoaster without eliminating feelings entirely, is consistent with what patients report in the literature.

On castor oil and peppermint for beard growth: no peer-reviewed evidence supports this combination as effective for facial hair stimulation. This is internet folklore, not pharmacology.

What did they get wrong (or right)?

The minoxidil cat concern is real, and they got it right. Minoxidil is genuinely toxic to cats, and dermal exposure is a documented risk pathway. A 2021 case series published in the Journal of Veterinary Emergency and Critical Care confirmed that topical minoxidil exposure, including secondary contact, can cause serious cardiovascular toxicity in cats. The creator's caution here is well-founded and not overstated.

The castor oil and peppermint claim is where things go sideways. There is no clinical evidence that Jamaican black castor oil or peppermint oil meaningfully stimulates beard or facial hair growth. Peppermint oil has one small animal study, Yoo et al. 2014 in Toxicological Research, suggesting it may promote hair growth in mice, but that is a long way from human facial hair data. Castor oil has essentially no peer-reviewed support for hair growth at all. It conditions hair that already exists, which is not the same thing.

Their characterization of 2.5 grams of gel as roughly a quarter to half of a standard dose is in the right ballpark. Standard testosterone gel doses typically range from 5 to 10 grams daily, so 2.5 grams sits at the lower end, consistent with microdosing protocols used in some gender-affirming care settings.

What should you actually know?

If you're early in a testosterone journey and watching this for reference, there are a few things worth keeping straight. First, two weeks is not enough time to draw conclusions about most physical changes. Beard growth, body composition shifts, and sustained voice changes typically take months to years, not days. Managing expectations here is not pessimism, it's just accurate.

Second, the emotional changes the creator describes, specifically feeling more stable rather than emotionally blunted, reflect a pattern seen in qualitative research on transmasculine hormone therapy. But individual responses vary, and emotional blunting is a real side effect that some people do experience, particularly at higher doses. It's worth monitoring, not dismissing.

Third, if you're considering alternatives to minoxidil because of cat safety concerns, talk to a dermatologist about other options. There are topical and oral treatments with actual clinical data behind them. Castor oil is not a substitute.

Finally, low-dose gel protocols are a real and legitimate approach used in gender-affirming care, but dosing decisions should be made with a clinician who can monitor hormone levels, not calibrated based on what other TikTok users are doing. Serum testosterone and estradiol levels matter here, and you can't gauge them by feel alone.