Total Testosterone

HormonesMeasured in ng/dL

What it measures

Total circulating testosterone, the large majority of which is protein-bound and not biologically available.

Why it matters

Genuine hypogonadism is a real condition with real consequences, and it is both under- and over-diagnosed depending on which door you walk through.

Where the claimed ranges actually sit

Measured in ng/dL. Each row is one claim about where your result should fall.

What a laboratory reportsWhat a seller markets as “optimal”

Laboratory reference range264–916 ng/dL

Harmonized reference ranges derived from population survey data

600–900 ng/dLC600–900 ng/dL

Testosterone replacement clinics and men's optimization platforms

›View as table

Claim	Range	Source
Laboratory reference range	264–916 ng/dL	Harmonized reference ranges derived from population survey data
600–900 ng/dL	600–900 ng/dL	Testosterone replacement clinics and men's optimization platforms

Where the sources disagree

The financial conflict here is more direct than anywhere else in the registry: the entity defining 'optimal' is usually the entity writing the prescription. Diagnosis properly requires two separate early-morning fasting draws with consistent symptoms, plus LH, FSH, SHBG, and prolactin to identify the cause. A single afternoon draw followed by a same-visit prescription is a sales process, not a diagnostic one.

The marketed ranges, examined

Each claim gets its strongest possible case before it gets its criticism. Several of these are substantially correct.

600–900 ng/dL

Promoted by testosterone replacement clinics and men's optimization platforms

CConfounded

The strongest case for it

Men in the bottom of the reference range do report more fatigue and lower libido on average, and the lower bound is derived from a population that includes many men with obesity and poor metabolic health.

What it leaves out

This range is promoted by the businesses that sell the prescription. Testosterone varies enormously by time of day (a single afternoon draw can read hundreds of ng/dL below the same man's morning value), and symptoms correlate poorly with total testosterone. Low total testosterone is frequently a consequence of obesity, poor sleep, or untreated sleep apnea, all of which are treatable causes rather than indications for lifelong therapy.

Before you act on your result

Draw before 10am after an overnight fast; confirm on a second separate day.
Interpret with SHBG: total testosterone is misleading when SHBG is abnormal.
Frequently reversible by treating obesity, sleep apnea, or sleep deprivation.
Exogenous testosterone suppresses fertility, which is often disclosed only in the fine print.

Last reviewed July 28, 2026How we grade evidence and attribute claims →

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