What is TRT? The five-minute version.

Testosterone replacement therapy (TRT) is prescription testosterone for men whose bodies no longer make enough of it — a medical condition called hypogonadism. It's long-term treatment, not a supplement: once you start, your own production typically drops further.

Who it's actually for

Treatment is appropriate when two things are true at once: consistent symptoms (fatigue, low libido, loss of morning erections, low mood) and blood tests confirming low testosterone on at least two separate morning draws.^[1] Symptoms alone aren't enough — everything on that list has other common causes, from sleep apnea to thyroid problems.

What the evidence says

In men with confirmed low testosterone, trials show consistent improvement in sexual function, mood, and bone density.^[1] On heart safety, the large TRAVERSE trial (2023) found no increase in major cardiac events, though it did find more atrial fibrillation and blood clots in treated men.^[2] For men with normal levels seeking energy or physique benefits, the evidence doesn't support treatment — and the FDA has warned against that use since 2015.^[3]

What treatment looks like when it's done right

• Two morning labs before any diagnosis
• A search for the cause, not just a prescription for the number
• A fertility conversation before the first dose — TRT suppresses sperm production
• Scheduled follow-up bloodwork, not "refill when you run out"

That's the five-minute version. The full picture — reading your labs, monitoring schedules, and how rules differ by state — is on our sister site.