What is the normal range for total testosterone in adult men?

Approximately 300-1000 ng/dL for most reference labs. On TRT, commonly 600-1100 ng/dL at trough. Levels decline ~1-2% per year after age 30. Ranges vary slightly between labs; trust your lab's reported reference interval.

Should I test in the morning?

For men not on TRT, yes, testosterone follows a diurnal rhythm peaking in early morning, so a 7-10 AM draw gives the most reproducible values. For men on TRT, timing relative to injection (trough) matters more than time of day; draw on the morning of the next injection before injecting.

What is the unit conversion between ng/dL and nmol/L?

Multiply ng/dL by 0.0347 to get nmol/L. Divide nmol/L by 28.84 to get ng/dL. Example: 600 ng/dL × 0.0347 = 20.8 nmol/L.

Why can my total T be normal but symptoms be bad?

Because symptoms track free testosterone more closely than total T, and free T depends on SHBG. High SHBG (from age, hyperthyroidism, liver disease) bind more of your total T, leaving less free. Calculate free T using the Vermeulen 1999 method from total T + SHBG + albumin to see the clinical picture.

What causes high total testosterone?

On TRT or AAS use, expected. Without exogenous input: testosterone-secreting tumors (testicular, adrenal), congenital adrenal hyperplasia, androgen-replacement misuse, or assay interference. Very high unexplained total T warrants endocrinology referral.

Total Testosterone

The headline hormone number on every TRT panel. Measures all testosterone in circulation, free, albumin-bound, and SHBG-bound combined.

Last updated: 2026-04-21 · Maintained by the VitaLog team

TL;DR. Normal adult male: ~300-1000 ng/dL. Draw at trough (morning before next injection if on TRT; 7-10 AM if natural). Total T alone can mislead, always pair with SHBG for free testosterone calculation.

Definition

Total testosterone is the sum of all testosterone in serum, the free (unbound) fraction plus testosterone loosely bound to albumin plus testosterone tightly bound to SHBG. It is the headline number reported by essentially every hormone panel. Measured by immunoassay or LC-MS/MS.

Testosterone is synthesized primarily by the Leydig cells of the testes in men (95%) with a small adrenal contribution (5%). Secretion is pulsatile with a pronounced diurnal rhythm, peaks around 7-8 AM, troughs in the late evening in naturally-producing men. On exogenous TRT, the diurnal rhythm flattens and the dosing schedule governs serum concentration.

Reference range

Population	Range (ng/dL)	Range (nmol/L)
Adult men 20-50	300-1000	10.4-34.7
Adult men 50-70	250-900	8.7-31.2
Adult men ≥70	200-850	6.9-29.5
Adult men on TRT (trough)	600-1100	20.8-38.2
Adult women	15-70	0.5-2.4

Conversion: ng/dL × 0.0347 = nmol/L; nmol/L × 28.84 = ng/dL.

What high total testosterone means

Exogenous input: TRT or anabolic-androgenic steroid use. Expected, not pathological.
Adrenal tumors: cortisol-secreting adenomas or carcinomas can co-secrete androgens.
Testicular tumors: rare, typically Leydig-cell.
Congenital adrenal hyperplasia: usually diagnosed in childhood.
Assay interference: some immunoassays cross-react with exogenous anabolic compounds or supplements.

What low total testosterone means

Primary hypogonadism: testicular failure (Klinefelter's, orchitis, trauma, chemotherapy).
Secondary hypogonadism: hypothalamic-pituitary dysfunction (pituitary tumor, prolactinoma, obesity-related HPG suppression, opioid use).
Age-related decline: gradual 1-2% per year after 30.
Acute illness, surgery, or caloric deficit: transient suppression.
Sleep deprivation: even 1 week of 5-hour sleep lowers testosterone by 10-15%.

Low total T with high SHBG often produces symptomatic low free T. Low total T with low SHBG (metabolic syndrome pattern) may have normal or near-normal free T, address metabolic health first.

When to test

Workup for symptoms of hypogonadism (low libido, fatigue, erectile dysfunction, cognitive fog, mood changes, loss of muscle mass).
Baseline before starting TRT.
Follow-up on TRT at 6 weeks, 3 months, 6 months, then annually.
Trough (morning before next injection) for TRT users on weekly or bi-weekly dosing.
7-10 AM for men not on TRT (diurnal peak).

SHBG, modulates free T
Free Testosterone, the bioactive fraction
Estradiol, aromatization product
Vermeulen free-T calculator
TRT bloodwork guide

FAQ

What is the normal range for total testosterone in adult men?: Approximately 300-1000 ng/dL for most reference labs. On TRT, commonly 600-1100 ng/dL at trough. Levels decline ~1-2% per year after age 30. Ranges vary slightly between labs; trust your lab's reported reference interval.
Should I test in the morning?: For men not on TRT, yes, testosterone follows a diurnal rhythm peaking in early morning, so a 7-10 AM draw gives the most reproducible values. For men on TRT, timing relative to injection (trough) matters more than time of day; draw on the morning of the next injection before injecting.
What is the unit conversion between ng/dL and nmol/L?: Multiply ng/dL by 0.0347 to get nmol/L. Divide nmol/L by 28.84 to get ng/dL. Example: 600 ng/dL × 0.0347 = 20.8 nmol/L.
Why can my total T be normal but symptoms be bad?: Because symptoms track free testosterone more closely than total T, and free T depends on SHBG. High SHBG (from age, hyperthyroidism, liver disease) bind more of your total T, leaving less free. Calculate free T using the Vermeulen 1999 method from total T + SHBG + albumin to see the clinical picture.
What causes high total testosterone?: On TRT or AAS use, expected. Without exogenous input: testosterone-secreting tumors (testicular, adrenal), congenital adrenal hyperplasia, androgen-replacement misuse, or assay interference. Very high unexplained total T warrants endocrinology referral.