The 5 Blood Markers Every Man Over 35 Should Track
Total T, free T, SHBG, estradiol, hematocrit. What each marker tells you, what to target, and how often to test.
- Total testosterone alone is not enough. Five markers together tell a story; one marker tells you almost nothing.
- SHBG is the hidden variable that explains why men with the same total T can feel completely different.
- Estradiol in men is not the enemy. It is the floor and the ceiling that both matter.
- Hematocrit is the safety check that gets ignored until it isn't, and then it isn't in a hurry.
- Test before 10 AM, fasted, and not the day after a hard workout. Otherwise you are measuring noise.
The first male hormone panel I ever ordered came back with seven numbers on it. Three of them I understood. The other four I had to look up. By the time I figured out what they meant and how they interacted, I was a year into this and had wasted a lot of mental energy on the wrong markers. The point of this article is to save you that year.
These are the five markers that matter, what each one tells you, what to target, and how often to test.
1. Total Testosterone
What it is: the total amount of testosterone circulating in your bloodstream, measured in nanograms per deciliter (ng/dL). This is the marker your PCP runs by default and the one that gets the most attention from clinics.
What the reference range says: roughly 264 to 916 ng/dL on most US lab reports. Wider on some, narrower on others.
What I look for: 600 to 900 ng/dL is where most men report feeling their best. Below 400, most men feel something. Above 1100, you are either on a high TRT dose or doing something supraphysiological. The reference range is not the target. The target is the level at which you feel like the best version of yourself, which for the vast majority of men is in the upper third of “normal.”
The trap with total T is that it is the marker that most clinics stop at. If you only ever look at this number, you are missing more than half of the picture. Two men with identical total T can feel completely different because of the next marker.
2. SHBG (Sex Hormone Binding Globulin)
What it is: the protein that binds testosterone in your bloodstream. Bound testosterone is not biologically active. Only the unbound (free) fraction is.
Why it matters: SHBG is the variable that decides what your real testosterone exposure looks like. A man with a total T of 550 and an SHBG of 70 nmol/L has less bioavailable testosterone than a man with a total T of 400 and an SHBG of 25. Same drug in the bloodstream, completely different functional level. This is why men get confused when their total T looks fine and they feel terrible.
Reference range: roughly 10 to 57 nmol/L, but the useful zone for most men is 20 to 45.
What pushes SHBG up: aging, alcohol, low calorie intake, hyperthyroidism, liver issues. What pushes it down: insulin resistance, obesity, hypothyroidism, anabolic steroid use. SHBG is also stubbornly genetic, which means some men run high or low for life and you have to dial the rest of the protocol around it.
The bloodwork wiki goes deep on the SHBG/free T relationship if you want the full mechanism.
3. Free Testosterone
What it is: the fraction of testosterone that is not bound to SHBG or albumin and is therefore biologically active. This is the testosterone that does the work.
Two ways to measure it. The accurate way is equilibrium dialysis. The convenient way is calculation from total T and SHBG. Most labs use calculation. The numbers are usually close enough, but if your panel is borderline and the decision matters, ask for the dialysis version.
What I look for: most men feel best with a free T in the upper third of the reference range. The reference range varies more than total T does, so I am hesitant to give you a single target number. Read it in context with your total T and your SHBG. If your total T is mid-range and your SHBG is high, your free T will be low and that is the reason you feel off, not the total number.
If your panel only shows total T and not free T, you are reading half the book. Always order both.
4. Estradiol (Sensitive Assay)
What it is: the form of estrogen that men have, derived mostly from testosterone via aromatization. Yes, men make estrogen. Yes, you need it.
Why it matters: estradiol in men is the marker that gets the most reactionary bro-science treatment. The forums are full of guys terrified of any estrogen in their bodies, taking aromatase inhibitors prophylactically, and crashing their estradiol into the floor. This is a mistake. Men need estradiol for bone density, cardiovascular health, libido (yes, libido), and joint function. Crashed estradiol feels worse than slightly high estradiol for most men.
What I look for: roughly 20 to 40 pg/mL on a sensitive (LC-MS/MS) assay. Below 15, most men feel terrible. Above 60, you start to see water retention, mood issues, and gynecomastia risk for some men. The sweet spot is wider than the forums suggest.
Critical: Always order the sensitive assay. The standard immunoassay is not accurate at the low levels men typically run. If your panel says “estradiol” and gives you a number under 15, ask whether it was a sensitive assay. If it wasn’t, you don’t know what your level is.
5. Hematocrit
What it is: the percentage of your blood volume that is red blood cells. Testosterone stimulates red blood cell production, so hematocrit drifts up on TRT.
Why it matters: this is the safety marker most TRT clinics check at baseline and then forget. High hematocrit thickens the blood and increases cardiovascular risk over time. The mechanism is well understood and the fix is usually simple, but only if someone is watching the number.
Reference range: roughly 38 to 50 percent for men.
What I look for: under 52 is generally considered safe. 52 to 54 is the warning zone where you should look at hydration, dose, and donation frequency. Above 54 and most providers will recommend a therapeutic phlebotomy (blood draw to bring the level back down). The good news: donating blood quarterly handles this for most men and you get to do something useful with the byproduct.
How often to test
Baseline panel before starting anything. Six weeks after any dose change. Quarterly once dialed in. Annual full metabolic and lipid panel alongside the hormone panel.
The reason for the cadence is that hormonal changes take weeks to show up in the bloodstream and weeks more to show up in how you feel. Testing too soon after a change tells you nothing useful. Testing too rarely lets things drift.
How to get tested
If you’re working with a provider, this is part of the deal. If you want to run your own panel, the simplest path in most US states is direct-to-consumer labs through Ulta Lab Tests or Marek Health. Both let you order a male hormone panel online without a prescription, walk into a Quest or LabCorp draw site, and get results back in a few days. A full panel runs $200 to $400.
In Maine, where I live, testosterone is exempt from the state’s controlled substance monitoring program under LD 1277, which makes direct-to-consumer access more straightforward than in most other states. One of the few times being in Maine has been a regulatory advantage for anything.
The point of all of this
You don’t need to memorize the reference ranges. You need to know what the markers are, why they interact, and what questions to ask the person reading your panel. If your provider is only running total T and saying “looks fine,” you can ask them to run the full panel. If they refuse, you have learned something about that provider.
Once you have the panel, the next article walks through how to read it: How to Read Your Own Bloodwork.