The conversation goes like this: you have been feeling off for months — tired in a way sleep does not fix, less sharp than you used to be, motivation somewhere between reduced and absent. You finally get your blood tested. A week later your GP or a nurse calls to confirm your results are normal. Everything is fine. You hang up and feel, somehow, worse than before — because now there is no explanation and no path forward.
This experience is common enough that it has generated a genuine debate in endocrinology about whether existing testosterone reference ranges are fit for purpose. The short answer is: they measure what is statistically typical in a broad population, which is not the same thing as what is hormonally optimal for an individual.
How Reference Ranges Are Constructed — And Why That Matters
Laboratory reference ranges for testosterone are established by testing large populations of men across wide age brackets and calculating what falls within two standard deviations of the mean. The result is a range wide enough to include the vast majority of men — typically 300 to 1,000 ng/dL for total testosterone in most US laboratories — regardless of how those men feel, how healthy they are, or what their individual baseline was at their hormonal peak.
The critical issue is that this population includes men at the lower end of hormonal health. A man of 55 with metabolic syndrome, chronic stress, poor sleep, and minimal exercise who tests at 310 ng/dL contributes to the normal range alongside a well-optimised, low-stress 25-year-old who tests at 850 ng/dL. The range accurately represents the population. It says much less about what level any given individual needs to function at their best.
In 2017, the Endocrine Society published a landmark study establishing harmonised reference ranges for testosterone using data from healthy, non-obese men aged 19–40 — men specifically selected to represent the upper end of male hormonal health, rather than the general ageing population. Their reference range came out at 264–916 ng/dL, with most healthy young men clustering in the upper half. The implication, as the study authors noted, is that comparing a 45-year-old's results to this range is very different from comparing them to a range derived from a mixed-age, mixed-health population.
The Personal Baseline Problem
There is a related issue that laboratory ranges cannot address: individual variation. Some men function optimally at 650 ng/dL. Some feel excellent at 500 ng/dL. Some begin experiencing symptoms well above the clinical threshold because their personal baseline — what their body produced in its prime — was substantially higher.
A man who tested at 780 ng/dL at 28 and now tests at 330 ng/dL at 44 has lost more than half his testosterone. Both numbers sit within the standard reference range. No alarm is triggered. But the biological reality of that decline is significant, and it can explain why this man does not feel the same as he did a decade ago — even if his current result is technically "normal."
Research published in the Journal of Clinical Endocrinology and Metabolism specifically examined men with testosterone in the low-normal range — 300 to 400 ng/dL — and found that many reported significant symptomatic burden: fatigue, reduced libido, difficulty maintaining muscle, mood disturbance. Treating by number alone would suggest no intervention is needed. Treating the person in front of you suggests a different conversation.
The Emerging Clinical Perspective: Functional Hypogonadism
The concept of functional hypogonadism — symptoms of low testosterone in the absence of frankly low levels — has gained traction in endocrinology over the last decade. The European Journal of Endocrinology and multiple guidelines from the European Association of Urology have recognised that testosterone treatment decisions should consider both the number and the clinical picture, not the number alone.
This means asking: does this man have symptoms consistent with low testosterone? Does the full hormone picture — including free testosterone and SHBG — paint a coherent story? Is there a plausible clinical explanation for those symptoms? If the answers are yes, a result of 310 ng/dL may warrant the same clinical consideration as a result of 240 ng/dL, even though only one crosses the classic threshold.
Conversely, a man at 320 ng/dL who is asymptomatic — sleeping well, maintaining muscle, energised, engaged — may need nothing beyond monitoring. The number matters. The person matters more.
What to Do If You Have Been Told You Are Fine
Start by requesting your actual numbers, not just a verbal summary. A result of 320 ng/dL and a result of 580 ng/dL both qualify as "within range," but they are not clinically equivalent. Get the numbers and understand where within the range you sit.
Then consider whether free testosterone and SHBG were included. Total testosterone alone misses the binding picture. A standard panel that shows normal total testosterone but high SHBG may reveal low free testosterone — and it is the free fraction that matters most for how you feel day to day.
Finally, if your symptoms are real and your numbers are on the lower end of the normal range, seek a second opinion from a provider who specialises in men's hormonal health. The right clinician will look at the full picture — your numbers, your symptoms, your history — and give you an honest assessment rather than a simple in-range/out-of-range verdict.
"Normal" is a population statistic. Your health is personal. The two deserve to be evaluated separately.
