Free vs. Total Testosterone: What Your Blood Test Is Really Telling You

Every time I get a blood test, there’s always one section that feels more like a puzzle than a clear answer: my testosterone numbers.

You get two values — Total Testosterone and Free Testosterone — but figuring out what they mean in real-world terms? That’s not so obvious.

I used to look at my results, see that I was in the “normal range,” and move on — meanwhile, I’d feel tired, weaker in the gym, and not quite dialed in.

Turns out, those numbers don’t tell the full story — unless you know what to look for.

What Is Total Testosterone?

This is the big number most doctors look at first. It includes all the testosterone floating around in your bloodstream — but here’s the catch:

Most of it is locked up.

It’s bound to two proteins — SHBG and albumin. When testosterone is bound, it’s like having money in a locked safe. You technically own it, but you can’t spend it.

So even if your total testosterone is in a “normal” range, that doesn’t mean your body can actually use it.

What Is Free Testosterone?

Free testosterone is the part that’s actually doing the work. It’s not bound to anything. It’s active, available, and ready to get things done.

It’s the hormone that directly drives:

Muscle growth and recovery
Strength and stamina
Energy and mental focus
Sex drive and performance
Confidence and motivation

You can have high total T on paper and still feel flat if your free T is low.

Quick Reference: What Your Numbers Should Look Like

Marker	What It Means	Normal Range (Adult Men)
Total Testosterone	All testosterone in blood (bound + free)	250-1,100 ng/dL
Free Testosterone	Active, usable testosterone	35-155 pg/mL
SHBG	Protein that binds testosterone	10-50 nmol/L
Free T %	Portion that’s actually usable	2-3% of total

Note: Ranges can vary slightly between labs. Always compare your results to your lab’s specific reference range.

So What’s Holding It Back?

Here’s where things get interesting — and where most guys get left in the dark.

If free testosterone is what really matters, you need to know what’s blocking it. That’s where three key markers come in: SHBG, albumin, and estradiol.

Let’s break them down in plain English.

1. SHBG (Sex Hormone-Binding Globulin)

SHBG is a protein made by your liver. Its job is to bind to sex hormones — including testosterone — and regulate how much is available in the bloodstream.

This might sound helpful (and it is, to a point), but here’s the issue: when SHBG levels get too high, it binds too much testosterone — and that reduces how much is free and active.

High SHBG = less free testosterone
SHBG tends to increase with age, stress, inflammation, certain medications, or low-fat/low-calorie diets

In simple terms: the more SHBG you have, the more your testosterone is locked away and unusable.

2. Albumin

Albumin is another protein in your blood. It also binds testosterone, but it does so more loosely than SHBG.

This means testosterone attached to albumin is still partially available — your body can use it when needed. That’s why albumin-bound testosterone is included in what some labs call “bioavailable testosterone.”

Albumin is not usually the problem — but understanding it helps give a full picture of your testosterone status.

3. Estradiol (E2)

Estradiol is a form of estrogen, and yes — men need it too.

Your body naturally converts some testosterone into estradiol via an enzyme called aromatase. This is normal and even necessary for:

Mood and brain function
Bone density
Sexual health

But too much estradiol can be a problem. It can:

Suppress testosterone production
Stimulate higher SHBG production
Lead to symptoms like fat gain, irritability, and low libido

On the flip side, too little estradiol can cause joint pain, depression, or lack of sexual sensitivity — even if testosterone is normal.

It’s not about eliminating estrogen — it’s about maintaining hormonal balance.

Advanced Bloodwork: What to Actually Test For

Most basic hormone panels just check total testosterone. That’s not enough.

If you’re serious about understanding (and improving) your testosterone, ask for the following:

Total Testosterone
Free Testosterone – The active form. Ask for the direct assay method.
SHBG – Shows how much testosterone is being locked down.
Albumin – Helps calculate bioavailable testosterone.
Estradiol (E2) – Should be in balance — not too high or too low.
Luteinizing Hormone (LH) – Reveals if your brain is signaling your testes to make testosterone. Low LH + low T may point to secondary hypogonadism.

What to Do If Free Testosterone Is Low

If your free T is low — but total T looks normal — you’ve got a clear mission.

Here’s where to start:

1. Lift Heavy, Train Smart

Focus on compound movements: squats, presses, deadlifts
Train 3–4 days a week
Avoid excessive cardio, which can spike SHBG

2. Eat to Support Hormones

Include healthy fats (eggs, olive oil, red meat, avocado)
Prioritize zinc, magnesium, vitamin D
Avoid extreme low-calorie or low-fat diets

3. Improve Recovery

Sleep at least 7–9 hours
Manage stress — cortisol and SHBG are tightly linked
Take rest seriously — that’s when hormones rebound

4. Consider Targeted Supplements (once basics are handled)

Tongkat Ali — may help reduce SHBG
Ashwagandha — supports hormonal balance and lowers cortisol
Boron — shown in some studies to increase free T and lower SHBG

Bottom Line: Read the Full Panel, Not Just the Headline

Total testosterone is the headline.

Free testosterone is the story.

If your free T is low, it doesn’t matter how high your total number is — your body won’t feel or perform like it should.

Don’t stop at the first number. Dig deeper. Understand what’s happening under the hood.

Stop Guessing. Start Owning It

Look at your last blood test.

Can you find your free T? SHBG? Estradiol?

If not, get a full hormone panel and stop guessing.

You’ve got two options:

Let your energy, strength, and drive decline and call it “getting older”
Or face the data, reclaim control, and build yourself back stronger than before

What’s it going to be?