Short answer: TRT means testosterone replacement therapy. It is a prescription treatment for men whose bodies do not make enough testosterone because of a medical condition called hypogonadism. Diagnosis takes symptoms plus repeat morning blood tests. TRT is a controlled medicine with real risks, including effects on fertility, so it needs regular monitoring.
TRT stands for testosterone replacement therapy. "Replacement" is the key word: the goal is to bring a man's testosterone, which is too low because of a medical problem, back into the normal range. It is different from using testosterone or related drugs at high doses to build muscle, which is misuse and can be dangerous.
Testosterone is the main male sex hormone. It is made mostly in the testicles, under signals from the pituitary gland in the brain. It plays a part in sperm production, sex drive, bone strength, muscle, red blood cell production and body hair.
Doctors split hypogonadism into two main types:
Testosterone also drifts down slowly with age, and it can be lower in men with obesity, type 2 diabetes or poor sleep. FDA labels for testosterone have said that its safety and effectiveness in men with low testosterone due only to aging have not been established. In June 2026, HHS announced that FDA had asked makers to remove that limitation from the labels. At the time of writing, this was a proposal.
Guidelines from the AUA and the Endocrine Society agree on careful testing:
Testosterone should not be started based on symptoms alone or a single test.
FDA-approved testosterone comes in several forms:
Each has trade-offs. Gels can rub off onto a partner or child through skin contact, which can cause unwanted effects in them. Some oral and injected products carry their own boxed warnings, for example about blood pressure increases or rare serious reactions after an injection.
Possible risks and side effects include:
TRT is not right for everyone. It is generally not used in men who are trying to have a child, or who have certain cancers, a very high red blood cell count or untreated severe sleep apnea.
Yes. Testosterone from outside the body tells the brain to stop sending signals to the testicles. That can lower sperm production, sometimes to zero. The AUA says men who want children should have a fertility evaluation before treatment, and men actively trying to conceive should not use testosterone. Other treatments can raise testosterone while protecting fertility in some men.
Men on TRT usually need:
Is TRT the same as taking steroids? No. TRT uses doses meant to bring testosterone back to the normal range in men with a diagnosed deficiency, with medical monitoring. Anabolic steroid misuse uses much higher doses and carries serious risks.
Is TRT for life? It depends on the cause. Some causes are permanent and need long-term treatment. Others, like some medicine or weight-related causes, may improve when the cause is treated.
Can women use TRT? No FDA-approved testosterone product exists for women in the US. This page is about testosterone therapy for men.
What is a normal testosterone level for men? Labs vary, but the AUA uses 300 ng/dL as a reasonable cut-off for low total testosterone, confirmed on two morning tests.
Does TRT cause heart attacks? In the large TRAVERSE trial, testosterone did not increase heart attacks or strokes in men with low testosterone compared with placebo. It did show more atrial fibrillation (3.5% vs 2.4%), acute kidney injury and lung clots.
If you have symptoms you think may be low testosterone, Dr. Vargas can review your history, order the right morning blood tests and explain whether TRT is an option for you, along with its risks.
Book a visit or call (210) 903-1030 In-clinic in San Antonio Yaso Wellness Health Clinic, 1907 Goliad Rd, San Antonio, TX 78223
Leticia Vargas, MD, OB/GYN. About Dr. Vargas
Education only, not medical advice or a diagnosis. In an emergency, call 911.
