Because no manufacturer has brought a female-dose testosterone product through FDA approval in the United States. Clinicians therefore prescribe either a compounded preparation or a fraction of a male product. Off-label prescribing is legal and common, but it does mean dosing relies on clinical judgement rather than a licensed regimen.
What it treats
Las Vegas treatment options: the evidence is narrow but real
Testosterone is marketed for energy, mood and focus, and the trial evidence behind Las Vegas prescribing supports a much narrower use than that. The strongest evidence is for hypoactive sexual desire in postmenopausal women. Trials show a measurable improvement in desire and arousal against placebo, and international consensus statements support prescribing for that indication.
Beyond that, the picture thins considerably. Women frequently report better energy, mood, concentration and muscle tone, and clinicians hear it often enough that it is hard to dismiss. The trial evidence for those outcomes is not strong, and we will say so rather than imply otherwise.
If low libido is the main problem, it is also worth checking the things that commonly sit underneath it: vaginal dryness, poor sleep, low mood and relationship factors. Treating those first sometimes removes the question entirely. Worth reading next: our clinicians, vaginal dryness and vaginal estrogen go further into it. We work through that list first in Las Vegas, and that sometimes ends the question without a testosterone prescription being written at all.
