“My testosterone came back normal” is one of the most common — and most incomplete — things men hear after bloodwork. In most cases, what was actually measured was total testosterone, which only tells part of the story. Free testosterone is often the more useful number, and it’s frequently left out entirely.
What Total Testosterone Measures
Total testosterone measures every form of testosterone in your blood — both the testosterone that’s active and usable by your body, and the majority that’s bound to proteins (mainly SHBG and albumin) and largely inactive. A standard testosterone test defaults to this number, which is why it’s the one most men have seen.
What Free Testosterone Measures
Free testosterone measures only the small percentage — typically 1-4% — that’s unbound and biologically available to your cells. This is the testosterone actually doing the work: supporting energy, muscle, mood, and libido. Two men can have identical total testosterone and very different free testosterone, depending on how much SHBG is binding it up.
Why This Gap Matters
If SHBG is elevated — which can happen with age, certain medications, thyroid conditions, or liver issues — total testosterone can look perfectly normal while free testosterone is genuinely low. This is one of the most common reasons men with real symptoms of low testosterone get told their labs are fine.
According to the Urology Care Foundation, a complete testosterone evaluation typically includes both total and free measurements specifically because total alone can miss clinically significant cases.
Should You Test Both?
If you’re investigating symptoms — low energy, reduced muscle mass, low libido — testing both total and free testosterone together gives a far more complete picture than either alone. If you’ve already had a “normal” total testosterone result but still have symptoms, free testosterone specifically is the logical next test.
You can order a Comprehensive Testosterone Profile, which includes both total and free measurements, directly through Personalabs — no doctor’s visit required, results delivered securely online.
Frequently Asked Questions
Do I need to fast before a testosterone test?
No fasting is required, but testosterone is highest in the morning, so testing between 7-10 AM typically gives the most accurate baseline reading.
Why would my total testosterone be normal but I still feel symptoms?
This is often explained by elevated SHBG binding up more testosterone than usual, leaving less free and available — which is exactly why free testosterone testing exists.
What’s considered a normal free testosterone level?
Reference ranges vary by lab and by age, generally falling in the range of roughly 5-21 ng/dL for adult men, though your specific lab’s range should be used to interpret your result.
Can free testosterone be tested on its own?
Yes, but testing it alongside total testosterone and SHBG gives your doctor much more context to work with than any single number alone.
How is low free testosterone typically treated?
Treatment depends on the underlying cause and severity, ranging from lifestyle changes to hormone therapy. Discuss your specific results with your doctor to determine the right approach.
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk to your doctor about your specific health situation.
