Getting testosterone replacement therapy starts with blood work confirming low levels, followed by a clinical evaluation of your symptoms. The American Urological Association defines low testosterone as a total testosterone level below 300 ng/dL, measured on at least two separate mornings. If your levels fall below that threshold and you have symptoms, you’re a candidate for treatment.
Recognizing the Symptoms
Low testosterone doesn’t announce itself with one obvious sign. It shows up as a cluster of changes that often develop gradually. The most common include low sex drive, erectile difficulties, persistent fatigue, loss of muscle mass, increased body fat (especially around the midsection), depressed mood, and difficulty concentrating. Some men also develop unexplained anemia, where red blood cell counts drop without a clear cause.
These symptoms overlap with many other conditions, from depression to thyroid disorders to poor sleep. That’s exactly why the diagnosis can’t rest on symptoms alone. Blood work is the gatekeeper.
The Blood Tests You’ll Need
Your testosterone level needs to be measured in the morning, ideally before 10:00 a.m. or within three hours of waking up. Testosterone peaks early in the day and drops as the afternoon progresses, so a late-day draw can produce misleadingly low numbers. Fasting beforehand is generally preferred, though the AUA notes the evidence for fasting specifically is weak.
One test isn’t enough. You need at least two low readings taken on separate days. Natural testosterone fluctuates by 10 to 15 percent day to day, which means two back-to-back measurements from the same person can differ by up to 30 percent. If your first result comes back below 300 ng/dL but the second is normal, your doctor may order a third to break the tie.
Beyond total testosterone, your provider will likely check free testosterone (the portion your body can actually use), along with other hormones that can reveal why your levels are low. Conditions like pituitary gland problems or certain medications can suppress production, and identifying the underlying cause changes the treatment approach.
Who to See
Your primary care doctor can order the initial blood work and start the conversation. Many primary care physicians prescribe TRT themselves if the diagnosis is straightforward. For more complex cases, you’ll be referred to a specialist. Urologists and endocrinologists are the two main options. Urologists tend to manage testosterone therapy within the broader context of men’s reproductive and sexual health, while endocrinologists focus on the hormonal system as a whole. Either can diagnose and treat you.
Men’s health clinics and telehealth platforms have also become common entry points. These can streamline the process, but make sure any provider orders proper lab work and does a physical exam rather than prescribing based on symptoms alone.
What Happens Before You’re Prescribed
Before starting TRT, your doctor will review your medical history, do a physical exam, and run several baseline blood tests beyond testosterone. These typically include a complete blood count (to check red blood cell levels), a PSA test (a prostate screening marker), and metabolic panels covering blood sugar and liver function. These aren’t formalities. They establish your starting point so your doctor can track changes once you’re on therapy.
Certain conditions rule out TRT entirely. You cannot start testosterone therapy if you have prostate cancer, breast cancer, or a red blood cell count that’s already too high (a condition called polycythemia). An unevaluated prostate lump also needs to be investigated first. Your doctor will screen for all of these before writing a prescription.
If you’re planning to have biological children, this is the time to speak up. TRT suppresses sperm production, sometimes severely. Restoring fertility after time on testosterone can be expensive and slow, with no guarantee of full recovery. Alternative treatments exist that can raise testosterone while preserving sperm count, so fertility goals need to be part of the conversation from day one.
Choosing a Delivery Method
Testosterone comes in several forms, and the right one depends on your lifestyle, comfort level, and how your body responds.
- Injections are the most common and typically the least expensive. They’re given into a large muscle (usually the thigh or buttock) on a weekly or biweekly schedule. Many men learn to do this at home. The FDA-approved dosing range for testosterone cypionate, the most widely prescribed injectable form, is 50 to 400 mg every two to four weeks, adjusted based on your response.
- Topical gels are applied to the skin daily, usually on the shoulders or upper arms. They deliver a steady dose and avoid the peaks and valleys that injections can produce. The tradeoff is that you need to avoid skin-to-skin contact with others at the application site until the gel dries, since testosterone can transfer to partners or children.
- Patches also deliver testosterone through the skin on a daily basis but can cause irritation at the application site for some men.
- Subcutaneous pellets are implanted under the skin (usually near the hip) during a brief office procedure and release testosterone slowly over three to six months. They’re convenient once placed but require a minor procedure each time they need to be replaced.
Your doctor will individualize the dose based on your age, how low your levels are, and how you respond. The goal is to bring testosterone into the normal range, not to maximize it.
What Monitoring Looks Like
Starting TRT isn’t a one-time event. You’ll need regular blood work to make sure the therapy is working and not causing problems. The typical monitoring schedule looks like this: blood counts checked at 3 months, again at 6 months, and again at 12 months. After the first year, expect a complete blood count every 6 months and a broader metabolic panel (covering blood sugar, liver enzymes, kidney function, and cholesterol) once a year.
The most common lab abnormality on TRT is a rise in red blood cell count. Testosterone stimulates red blood cell production, which can thicken the blood and increase the risk of clotting. If your levels climb too high, your doctor may lower the dose, switch delivery methods, or temporarily pause treatment. PSA levels also get tracked to monitor prostate health, since testosterone can stimulate prostate tissue and cause urinary symptoms in some men.
Most men notice improvements in energy, mood, and libido within the first few weeks to months, though the full effects on body composition (more muscle, less fat) can take three to six months to become apparent. If your symptoms don’t improve despite normal testosterone levels on blood work, your doctor will re-evaluate whether something else is going on.
Costs and Access
Insurance coverage for TRT varies widely. Most plans cover it when you have a documented diagnosis of hypogonadism with confirmed low lab values, but some require prior authorization. Injectable testosterone cypionate is often the most affordable option, with out-of-pocket costs running as low as $30 to $50 per month without insurance. Gels and patches tend to cost more, and pellet implantation involves a procedure fee on top of the medication cost.
Telehealth TRT clinics have grown rapidly and can be convenient, but they sometimes charge monthly membership fees that add up. Compare the total annual cost against what you’d pay through a traditional provider and your insurance plan before committing.