You got your lab results back. Great! Now you're staring at a page full of numbers, abbreviations, and reference ranges that might as well be written in another language.
I get this question constantly: "What do these numbers actually mean?" So let me walk you through the most important markers we look at, what they tell us, and what actually matters.
The Big One: Total Testosterone
This is what most people focus on first, and for good reason - it's the most straightforward number.
What it measures: All the testosterone in your blood, both the stuff your body can actually use and the stuff that's bound up to proteins.
Optimal for most men: 600-900 ng/dL
Here's the problem with just looking at total testosterone: the "normal" range is huge. You could have a total testosterone of 300 ng/dL and technically be "normal" - but you'd probably feel terrible.
What I actually care about: Not just whether you're in the reference range, but where you are in that range and how you're feeling. A guy with total testosterone of 350 who's tired all the time and can't lose weight isn't "fine" just because he's technically in range.
The One That Really Matters: Free Testosterone
This is the number I pay the most attention to, and here's why.
What it measures: The testosterone that's actually available for your body to use. Most of your testosterone is bound to proteins and can't be used. Free testosterone is what's left over and bioavailable.
Optimal for most men: 20-25 ng/dL
You can have decent total testosterone but low free testosterone - and that's the scenario where you'll feel all the symptoms of low T despite your total number looking okay.
Why this happens: A protein called SHBG (we'll get to that in a minute) binds up your testosterone and makes it unavailable. Some guys naturally have high SHBG, which means even with decent total testosterone, they don't have much free testosterone actually working for them.
SHBG: The Complicated One
Sex Hormone Binding Globulin. Yes, it's a mouthful.
What it does: SHBG is a protein that binds to testosterone and makes it unavailable for your body to use. Think of it like a sponge soaking up your testosterone.
High SHBG: Your total testosterone might look fine, but your free testosterone is low because too much is bound up. Common causes include aging, low-fat diets, hyperthyroidism, or just genetics.
Low SHBG: More free testosterone available, which sounds great - but very low SHBG can indicate insulin resistance, metabolic syndrome, or liver issues.
The sweet spot? Middle of the range, usually 20-40 nmol/L.
Estradiol (E2): Yes, Men Need This Too
A lot of guys freak out when they see estrogen on their lab results. "Wait, isn't that a female hormone?"
Yes and no. Men need estrogen too. Your body converts some testosterone into estradiol, and you need a certain amount for bone health, brain function, libido, and cardiovascular health. Different labs use different tests for estradiol, so ranges vary slightly. We always interpret your results in context.
What it measures: The amount of estradiol (a form of estrogen) in your blood.
Optimal for most men: 20-30 pg/mL
Too low: Joint pain, low libido, mood issues, brittle bones. Some guys on TRT crash their estrogen trying to "control" it and feel worse than before they started treatment.
Too high: Water retention, mood swings, gynecomastia (breast tissue development), and potentially reduced effectiveness of testosterone.
What I do: Monitor it, but I rarely treat high estrogen unless you're having symptoms. If we keep your testosterone dose appropriate, estrogen usually takes care of itself.
PSA: The Prostate Marker
Prostate-Specific Antigen. We check this before starting TRT and monitor it regularly.
What it measures: A protein produced by your prostate. Elevated PSA can indicate prostate enlargement, inflammation, or rarely, prostate cancer.
What I watch for: Rapid increases more than absolute numbers
Important to know: PSA can temporarily spike after ejaculation, exercise, or prostate exams. If it's elevated, we'll recheck it before panicking.
TRT doesn't cause prostate cancer, but we monitor PSA to catch any issues early. If your PSA starts climbing rapidly, we investigate.
Hematocrit: The Blood Thickness Marker
This is one people don't think about much until it becomes a problem.
What it measures: The percentage of your blood that's made up of red blood cells. Basically, how thick your blood is.
What I watch for: Values above 52-54%
Why it matters on TRT: Testosterone can increase red blood cell production, which can make your blood thicker. Too thick, and you increase risk of blood clots, stroke, or heart attack.
How we manage it: If hematocrit rises too high, your provider may adjust your plan — sometimes that means lowering the dose or having you donate blood. The key is catching it early.
The Metabolic Markers
These aren't hormone-specific, but they matter a lot for overall health and TRT safety.
Lipid Panel (Cholesterol): We monitor total cholesterol, LDL, HDL, and triglycerides. TRT can affect these, and we want to make sure we're not making your cardiovascular risk worse.
Liver Enzymes (ALT, AST): Make sure your liver is handling everything well. Injectable testosterone is generally very easy on the liver, but we check anyway.
Kidney Function (Creatinine, BUN): Again, just making sure everything's working as it should.
What "Optimal" Actually Means
Here's the thing: I don't only treat lab numbers. I treat people.
You could have "perfect" labs on paper and still feel terrible. Or you could have numbers that seem borderline and feel amazing. The goal isn't to hit some magic number - it's to help you feel good and function well.
Here’s a general ballpark of where many men feel their best — though it depends on age, health, and how you respond.
- Total Testosterone: 700-900 ng/dL
- Free Testosterone: 20-25 ng/dL
- Estradiol: 20-30 pg/mL
- SHBG: 20-40 nmol/L
- Hematocrit: Below 52%
- PSA: Below 2.5 ng/mL and stable
But these are guidelines, not rules. Your optimal levels depend on how you feel, your age, your health goals, and your individual response.
When to Retest
Before starting TRT: Comprehensive baseline - everything we've discussed plus a few other markers.
6-8 weeks after starting: We typically recheck labs to see how your body’s responding — adjustments are made only as needed and under supervision.
3-4 months: Once stable, we check labs every 3-4 months to make sure everything stays in range.
If something changes: New symptoms, different energy levels, any concerns - we check labs to see what's happening.
Questions You're Probably Wondering
"My doctor said my testosterone is 'normal' but I feel terrible. What gives?"
The reference range is based on a huge population of men from ages 20-80+. "Normal" includes a 70-year-old man with declining hormones and a 25-year-old in his prime. Just because you're in range doesn't mean you're at your optimal level.
"Do I need to test at a specific time of day?"
Yes! Testosterone levels are highest in the morning (around 8am) and drop throughout the day. Always test in the morning, fasted if possible, for the most accurate baseline.
"How much do these labs cost?"
Initial comprehensive panel with consultation runs about $250. Follow-up labs (smaller panel) are around $99. We use the same labs your doctor would use - LabCorp or Quest.
"Can I use labs from my regular doctor?"
Absolutely, as long as they're recent (within the last 3 months) and include the markers we need. Bring them to your consultation and we'll review them together.
"Numbers matter, but how you feel matters more. Labs guide treatment, but your symptoms and quality of life are what we're actually trying to improve."
The Bottom Line
Lab results can feel overwhelming, but they're just data points that help us figure out what's going on with your hormones. They're not the whole story - they're just one piece of the puzzle.
When we review your labs together, I'll explain what each number means for you specifically, what we're going to monitor, and what we're trying to achieve. No medical jargon, no confusing terminology - just straightforward explanations.
Your job isn't to become an endocrinologist. Your job is to pay attention to how you feel, communicate any changes or concerns, and show up for your follow-up labs. we'll handle the rest.
This content is for educational purposes only and not a substitute for individualized medical advice. Always consult a qualified healthcare provider for personalized guidance on lab interpretation and treatment decisions.