Testosterone replacement therapy (TRT) is a prescription treatment for men with low testosterone associated with a medical condition. To get TRT in the United States, schedule an appointment with a primary care clinician, urologist or endocrinologist. You will usually need symptoms of testosterone deficiency plus two separate early-morning blood tests showing consistently low testosterone. The clinician should then investigate the cause, discuss fertility and treatment risks, and set up follow-up monitoring.

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The TRT Process at a Glance

Step What Usually Happens
1. Medical appointment Discuss symptoms, health history, medications, sleep and fertility plans
2. First blood test Early-morning total testosterone test
3. Repeat test A second test on a different morning
4. Cause assessment Tests may include LH, FSH and other hormone or health checks
5. Treatment decision The clinician decides whether TRT is medically appropriate
6. Monitoring Follow-up visits and blood tests check testosterone levels, side effects and safety

1. Book an Appointment With the Right Clinician

Start with a primary care clinician. A urologist can help when erectile dysfunction, fertility, testicular problems or prostate concerns are involved. An endocrinologist may be the right choice when a pituitary, hormonal or complex medical cause is suspected.

Before the appointment, write down:

  • Low libido or fewer spontaneous erections
  • Erectile difficulties
  • Fatigue or reduced energy
  • Loss of muscle or strength
  • Infertility concerns
  • Changes in mood or concentration
  • Sleep problems
  • Current medications, including opioids or corticosteroids
  • Whether you want children soon

Symptoms do not establish low testosterone on their own. Fatigue, low libido, obesity, poor sleep, depression, medications and other illnesses can cause similar symptoms.

2. Get Two Early-Morning Testosterone Tests

A proper diagnosis normally requires at least two testosterone measurements taken on separate mornings. Testing usually takes place between approximately 7 a.m. and 10 a.m., when testosterone levels are often highest. The Endocrine Society recommends morning fasting testing. The American Urological Association requires two early-morning total testosterone measurements.

Many clinicians use 300 ng/dL as a practical threshold for low total testosterone. The result still needs to be considered alongside your symptoms, test timing, laboratory method and repeat result. One low reading is not enough to start TRT safely.

Do not restrict sleep, overtrain or test while acutely ill to try to lower the result. Health, nutrition, exercise and medication changes can affect testosterone measurements.

3. Find Out Why Testosterone Is Low

When results are consistently low, the clinician should investigate the cause before deciding on treatment.

Follow-up tests may include:

  • LH and FSH, which help distinguish testicular failure from a pituitary or hypothalamic problem
  • Complete blood count or hematocrit
  • Prostate-specific antigen testing when appropriate for age and risk
  • Hormone, thyroid or pituitary testing when clinically indicated
  • Semen or fertility testing if you are trying to conceive

The Endocrine Society recommends determining whether hypogonadism is primarily testicular or related to the pituitary or hypothalamus. Reversible contributors, including obesity, some medications and untreated sleep problems, may need attention first.

4. Discuss Whether TRT Is Appropriate for You

TRT is intended for diagnosed hypogonadism. FDA-approved testosterone products are prescription medicines for men with low testosterone associated with a medical condition.

A clinician may delay or avoid TRT if you:

  • Are trying to have children soon
  • Have known or suspected prostate or breast cancer
  • Have a high red blood cell count
  • Have untreated severe sleep apnea
  • Have severe urinary symptoms from an enlarged prostate
  • Have uncontrolled heart failure
  • Had a heart attack or stroke within the previous six months
  • Have certain blood-clotting risks

External testosterone can suppress sperm production, sometimes substantially. Tell the clinician about your fertility plans before starting treatment. Depending on the cause of low testosterone, another treatment may be more suitable.

5. Choose a Medically Appropriate TRT Form

Prescription testosterone is available in several forms:

  • Injections
  • Topical gels
  • Transdermal patches
  • Buccal products applied to the gum or inner cheek

The choice depends on your preferences, insurance, ability to apply or inject the medicine correctly, fertility plans, side-effect risks and treatment schedule. The goal is to restore testosterone to a normal physiological range, not to use bodybuilding-level doses.

Do not change the dose or injection frequency without medical guidance. Higher doses can increase risks without providing a valid treatment benefit.

6. Expect Ongoing Monitoring

TRT requires follow-up. Monitoring usually checks:

  • Testosterone level and symptom response
  • Hemoglobin and hematocrit
  • Blood pressure
  • Prostate risk when appropriate
  • Side effects and treatment adherence

The American Urological Association states that a hematocrit of 54% or higher while taking testosterone requires intervention. The Endocrine Society recommends reviewing treatment response and adverse effects after therapy begins, with prostate monitoring based on individual risk.

Avoid Online Shortcuts and "Testosterone Boosters"

Avoid websites that offer testosterone after one unconfirmed test, sell injections without a prescription or promise bodybuilding results. The FDA warns that unsafe online pharmacies may sell counterfeit, unapproved or improperly handled medicines, sometimes without requiring a prescription.

A legitimate TRT evaluation starts with a medical appointment, properly timed testing, an assessment of the cause and a plan for follow-up.