Getting testosterone replacement therapy starts with a blood test and a conversation about your symptoms. Doctors won’t prescribe TRT based on how you feel alone. You need at least two blood draws showing low testosterone levels, plus symptoms that match the clinical picture of hypogonadism. Here’s what the process looks like from start to finish.
Which Doctor to See
Your primary care doctor can diagnose low testosterone and prescribe TRT. Many do this routinely. If your case is complicated, or if your primary care provider isn’t comfortable managing hormone therapy, you’ll likely be referred to a urologist or an endocrinologist. Urologists handle male reproductive health broadly, while endocrinologists specialize in hormonal conditions including low testosterone, thyroid disorders, and pituitary problems. Either specialist can manage the full process from diagnosis through ongoing monitoring.
Some men go directly to hormone clinics or telemedicine platforms that specialize in TRT. These can streamline the process, but they vary widely in quality. A provider who orders thorough bloodwork and discusses risks before prescribing is a good sign. One who rubber-stamps a prescription after a five-minute call is not.
The Blood Tests You’ll Need
The cornerstone of diagnosis is a morning blood draw for total testosterone. Levels fluctuate throughout the day and peak between 7 a.m. and 9 a.m., so your doctor will want the sample taken early. You’ll need at least two low readings on separate days before a diagnosis can be made. This isn’t optional: insurance companies, including major carriers like Aetna, specifically require two confirmed low morning testosterone levels before they’ll authorize coverage.
The threshold that triggers a diagnosis depends on which guidelines your doctor follows. The American Urological Association uses 300 ng/dL as the cutoff. The Endocrine Society sets it slightly lower at 264 ng/dL. For reference, the normal adult male range runs from roughly 193 to 824 ng/dL, though labs vary slightly in how they define their reference range.
Beyond total testosterone, your doctor will likely order additional blood work to understand what’s causing the low levels. Two hormones produced by the pituitary gland, LH and FSH, help pinpoint the source of the problem. If your testosterone is low but LH and FSH are high, the issue is in the testes themselves (primary hypogonadism). If all three are low, the problem originates in the brain’s signaling system (secondary hypogonadism). This distinction matters because secondary hypogonadism can sometimes be caused by treatable conditions like a pituitary tumor, obesity, or certain medications. Expect a baseline hematocrit (red blood cell concentration), PSA level if you’re over 40, and possibly thyroid and prolactin tests as well.
Symptoms That Support a Diagnosis
Low blood levels alone aren’t enough. Doctors look for a pattern of symptoms that align with what the numbers show. The most common ones include:
- Low sex drive or difficulty getting erections
- Fatigue and trouble concentrating
- Loss of muscle mass or increased body fat
- Mood changes, particularly depression or irritability
- Sleep problems like insomnia
- Bone loss (sometimes discovered incidentally on a scan)
Some men with objectively low testosterone have no symptoms at all. In those cases, most guidelines recommend against starting TRT since the point of treatment is to relieve symptoms, not to chase a number. When you talk to your doctor, be specific and honest about what you’re experiencing. Vague complaints are harder to act on than concrete descriptions: “I’ve lost interest in sex over the past year” carries more diagnostic weight than “I just don’t feel like myself.”
Conditions That Can Disqualify You
Before prescribing TRT, your doctor will screen for conditions that make testosterone therapy unsafe. Untreated prostate cancer and breast cancer are absolute contraindications. Men at elevated risk for prostate cancer, including those with a first-degree relative who had it and African American men with a PSA above 3 ng/dL, face additional scrutiny. If your hematocrit is already high (above 54%), TRT will be held off until that normalizes, since testosterone stimulates red blood cell production and pushing hematocrit too high raises the risk of blood clots.
Doctors will also evaluate whether something reversible is driving your low levels. Obesity, opioid use, sleep apnea, and excessive alcohol consumption can all suppress testosterone. Addressing those issues first sometimes brings levels back up without TRT. If you’re trying to conceive, that’s another important conversation, as TRT suppresses sperm production and can cause infertility while you’re on it.
Choosing a Treatment Method
Once you’re approved for TRT, you and your doctor will choose a delivery method based on your lifestyle, comfort level, and how stable you want your testosterone levels to be. The main options break down like this:
- Injections are the most common and typically the cheapest. Testosterone cypionate and enanthate are injected every one to two weeks. A longer-acting injectable (testosterone undecanoate) requires only about four doses per year, with injections at weeks 0 and 4 and then every 10 weeks. Many men learn to self-inject at home.
- Topical gels are applied daily and absorb through the skin. They provide steadier day-to-day levels than injections but require care to avoid transferring the gel to partners, children, or pets through skin contact.
- Patches are applied every 24 to 48 hours and maintain levels within the normal range for most men. Skin irritation at the application site is the most common complaint.
- Pellets are implanted under the skin in a quick office procedure and replaced every three to four months. They offer the most hands-off experience but require a minor incision each time.
- Oral capsules are a newer option taken daily with a meal containing fat. They avoid the first-pass liver metabolism that made older oral formulations risky.
- Nasal gel is applied inside the nostrils three times daily. It works but the frequent dosing schedule makes it less popular.
Injections tend to produce peaks and troughs in testosterone levels between doses, which some men notice as energy or mood fluctuations toward the end of a cycle. Gels and patches produce more even levels but demand daily consistency. There’s no single best option; it depends on what fits your routine and what your insurance covers.
What Happens After You Start
TRT isn’t a set-it-and-forget-it treatment. You’ll have follow-up bloodwork at 3 to 6 months after starting, then annually. The timing of that blood draw depends on your delivery method. If you’re on injections, your doctor will want a sample taken midway between doses to get a realistic average. For gels, the draw happens 2 to 8 hours after application, at least a week into treatment.
At each check, your doctor will monitor your testosterone level to confirm it’s in the target range, your hematocrit to watch for excessive red blood cell production, and (for men over 40 or those at higher risk) your PSA. Men with osteoporosis at baseline may get a bone density scan after one to two years of treatment to assess improvement.
Most men notice improvements in energy, libido, and mood within the first few months, though changes in body composition and bone density take longer. If symptoms don’t improve and your blood levels are in range, your doctor may reconsider whether low testosterone was actually the cause of your symptoms. Not every case of fatigue or low libido is a testosterone problem, and TRT won’t fix what it didn’t cause.
Navigating Insurance Coverage
Most insurance plans cover TRT for a confirmed diagnosis of hypogonadism, but prior authorization is common. The insurer will typically want documentation of two low morning testosterone levels, evidence of symptoms, and confirmation that the tests were done correctly. Generic testosterone cypionate injections are usually the easiest to get covered, often costing very little with insurance. Brand-name gels, patches, and pellets can be significantly more expensive and may require a step therapy process, where your insurer asks you to try a cheaper option first.
If you’re paying out of pocket, injectable testosterone cypionate is by far the most affordable option, often under $50 per month. Gels and pellets can run several hundred dollars monthly without coverage. Ask your doctor’s office about prior authorization requirements upfront so you aren’t surprised by a denial at the pharmacy.