Who TRT is for
TRT is for men with hypogonadism: low testosterone from a problem with the testicles, the pituitary gland or the hypothalamus. Causes include injury, chemotherapy or radiation, and certain genetic conditions.
The Endocrine Society says to diagnose low testosterone only when both are true: symptoms or signs of deficiency, and consistently low testosterone on fasting morning blood tests taken on two separate days. Symptoms can include low sex drive, erectile problems, fatigue, loss of muscle and low mood, but many of these have other causes too.
Cleveland Clinic advises against TRT for bodybuilding or to slow normal aging. For the difference between medical TRT and steroid misuse, see TRT vs steroids.
How low testosterone is diagnosed
- Two morning tests of total testosterone on different days, fasting. Read about testosterone blood tests, total testosterone and free testosterone.
- Free testosterone if total testosterone is borderline or SHBG (the protein that carries testosterone) is unusual.
- LH and FSH to tell whether the problem starts in the testicles or the brain.
- Baseline safety labs, typically hematocrit and PSA, plus others your clinician picks.
Forms of TRT
| Form | How it's used |
|---|---|
| Skin gel | Applied daily |
| Injection into muscle | Every 1 to 2 weeks; a long-acting type is given in a clinic about every 10 weeks |
| Injection under the skin | Weekly |
| Patch | Daily |
| Pellets | Placed under the skin every 3 to 6 months |
| Buccal tablet, nasal gel, oral capsule | One to three times a day |
How TRT is monitored
- Testosterone level: rechecked after starting, with the aim of a mid-normal level.
- Hematocrit: TRT can raise red blood cells. The Endocrine Society advises pausing therapy if hematocrit goes above 54%. See high hematocrit on TRT.
- Prostate: PSA and an exam at baseline and 3 to 12 months after starting, then routine screening.
- Blood pressure: the FDA now requires a blood pressure warning on all testosterone products.
- Symptoms: if testosterone is normal but symptoms haven't improved after 3 to 6 months, Cleveland Clinic says a clinician may suggest stopping.
Fertility, and how to get started
TRT lowers sperm production and can cause infertility. If you want biological children soon, tell your clinician first; the Endocrine Society recommends against TRT in men planning a pregnancy in the near term.
Gabriel can help you find and book a practitioner who manages testosterone therapy, and a free Gabriel account pays cost-plus prices on lab tests. See how to get TRT online and TRT side effects.
Common questions
What does TRT stand for?
Testosterone replacement therapy: prescription testosterone for people diagnosed with low testosterone.
Is TRT for life?
Often. Your body may make less of its own testosterone while you're on it, so stopping usually brings symptoms back. Talk with your clinician before stopping.
What testosterone level qualifies for TRT?
There's no single number for everyone. Diagnosis needs symptoms plus consistently low fasting morning levels on two tests, judged against your lab's range.
Does TRT raise heart attack risk?
In February 2025 the FDA removed the boxed warning about heart risk after the large TRAVERSE trial found no increase in major heart events. It added a warning that testosterone can raise blood pressure.
Can women take TRT?
TRT as described here is for men with hypogonadism. Testosterone use in women is a separate topic; ask a clinician who specializes in hormones.
Sources
- Testosterone replacement therapy (TRT) Cleveland Clinic
- Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline Journal of Clinical Endocrinology & Metabolism (Bhasin et al., 2018)
- Testosterone injection MedlinePlus, National Library of Medicine
- FDA issues class-wide labeling changes for testosterone products U.S. Food and Drug Administration
This guide is general information, not medical advice. It does not replace a visit with a licensed clinician. Gabriel membership is not health insurance.