When men get their testosterone checked, they’re usually told one simple number: total testosterone level.

But total testosterone alone rarely reflects how you actually feel — because only a portion of that testosterone is usable by your body. Understanding the difference between total testosterone, free testosterone, and bioavailable testosterone is the key to understanding whether your levels are truly “normal.”

Let’s break it down

Total Testosterone vs. Free Testosterone vs. Bioavailable Testosterone

Total Testosterone

This is the total amount of testosterone in your bloodstream — both the portion your body can use and the portion it cannot.

SHBG-Bound Testosterone (Not Usable)

About two-thirds of your testosterone is tightly bound to a protein called SHBG (sex hormone–binding globulin).

When testosterone is attached to SHBG:

• It cannot enter your cells

• It cannot activate receptors

• It cannot produce benefits

In other words: this portion is non-functional testosterone.

Albumin-Bound Testosterone (Usable)

The other portion is loosely bound to albumin, and your body can use it.

Free Testosterone (Fully Usable)

This is testosterone floating freely in your bloodstream — not bound to any proteins — and is directly available for your cells to use.

Bioavailable Testosterone = Free + Albumin-Bound

This is the testosterone your body can actually use, and it’s often the most important number when we’re evaluating energy, libido, mood, strength, and overall well-being.

The Gas Tank Analogy (Explains It Perfectly)

Think of testosterone like gasoline.

• Total testosterone = all the gas you own (in your tank + in gas cans)

• Bioavailable testosterone = the gas actually in your fuel tank

• SHBG-bound testosterone = the gas cans sitting in your trunk

You may technically “have” 20 gallons of gas…

but if only 5 gallons are in your tank, your car isn’t going anywhere.

This is why two men with the exact same total testosterone level can feel completely different.

If your usable testosterone is low, you will feel low — even if your total number looks “normal” on paper.

So What’s Considered a “Normal” Testosterone Level?

Reference ranges differ slightly between labs, but average values look like this:

• Total Testosterone: 300–1100 ng/dL

• Bioavailable Testosterone: 60–220 ng/dL

These are broad ranges — intentionally — because they include men from age 18 all the way to age 80+.

That’s where the problem begins.

“Normal” Doesn’t Mean Optimal

A 35-year-old man with a testosterone level of 350 ng/dL is considered “normal.”

But that 350 is the same testosterone level an 80-year-old man may have.

If you’re in your 30s, 40s, or 50s and showing symptoms — fatigue, low motivation, irritability, low libido, weight gain, poor sleep, brain fog — it’s not enough to look at a number in isolation and call it “normal.”

Too many men get told:

“You’re fine. Your labs are normal.”

And then they get labeled with:

• Depression

• Burnout

• Anxiety

• “Just getting older”

…when the real issue is suboptimal testosterone and low bioavailable levels.

Symptoms Matter Just as Much as the Number

This is why at Evolve Wellness, I don’t diagnose based solely on total testosterone.

I look at:

• Total testosterone

• Free testosterone

• Bioavailable testosterone

• SHBG

• Blood counts

• Thyroid markers

• Metabolic markers

• Your actual symptoms

• Your overall picture

Hormones shouldn’t be treated by numbers alone.

They should be treated within the context of how you feel, how you function, and what’s happening physiologically.

How I Determine Whether Testosterone Optimization Is Right for You

Rather than checking one number and sending you on your way, I take a more complete approach:

• Are you tired even with good sleep?

• Do you feel unmotivated or “flat”?

• Has your body composition changed?

• Is your libido lower than usual?

• Are you irritable or more on edge?

• Do you feel like yourself — or not?

Then I combine your symptoms with your lab findings to make a thoughtful, individualized decision.

Testosterone therapy is not about chasing high numbers — it’s about restoring balance so you can feel like yourself again.

The Bottom Line

“Normal” testosterone doesn’t always mean optimal testosterone.

If your levels fall within the lab’s reference range but your symptoms tell a different story, it’s worth taking a closer look — with someone who understands how to interpret the full hormone picture.

You deserve to feel good in your body, to have your energy back, and to function at your best.

If you’re wondering whether your testosterone is truly normal, I’d be happy to help.

Schedule a consultation and we’ll review your labs, symptoms, and goals — together.

Robin Amyett, APRN